BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Sub-barrier transfer reactions and the nuclear Josephson effect DTSTART;VALUE=DATE-TIME:20240529T073000Z DTEND;VALUE=DATE-TIME:20240529T080000Z DTSTAMP;VALUE=DATE-TIME:20260618T074230Z UID:indico-contribution-23758@indico.ific.uv.es DESCRIPTION:Speakers: Lorenzo Corradi (INFN - Laboratori Nazionali di Legn aro\, Legnaro (Padova)\, Italy)\nA series of sub-barrier transfer experime nts have been recently carried out at LNL\, with reaction products detecte d in inverse kinematic and at forward angles with the large solid angle ma gnetic spectrometer PRISMA. We measured transfer cross sections far below the Coulomb barrier\, making excitation functions down to very low energie s. At these low energies\, corresponding to very large distances of closes t approach\, the nuclear absorption is small [1\,2\,3] and one can probe n ucleon-nucleon correlation properties. 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 energ y range\, both in magnitude and slope [2]. The fact that most of the cross section of the two neutron transfer channel is in the ground to ground st ate transition has been further confirmed by a second experiment [4]. Prot on transfer channels have been also analyzed [5]\, showing a large yield i n the population of two proton transfer channels\, indicating the presence of strong proton-proton correlations.\nThese kind of studies\, where we f ollowed the behaviour of the transfer probabilities by varying the in tern uclear distance\, turned out to be fundamental to probe nucleon-nucleon co rrelation effects\, where the interaction between the nuclear surfaces pla ys a fundamental role. In this context\, the coupling of the AGATA gamma a rray to PRISMA offered a unique opportunity to study a nuclear (alternatin g current (AC)) Josephson-like effect [6]\, with Cooper-pair tunnelling be tween superfluid nuclei\, whose manifestation has been recently proposed [ 7] using the data of Refs. [2\,4] as a stepping stone. Predictions have be en made of a specific gamma strength function associated with the dipole o scillations generated by the\, mainly successive\, two neutron transfer pr ocess. In a very recent experiment carried out at LNL with PRISMA+AGATA we directly tested for the\nfirst time the possible manifestation of this im portant effect of Cooper pair behaviour\, observed to date only in condens ed matter physics.\nAfter a general overview on the subject\, the talk wil l focus on new results\, addressing the new achievements and the critical issues.\n\n[1] L. Corradi et al.\, Phys. Rev. C 84\, 034603 (2011).\n[2] D . Montanari et al.\, Phys. Rev. Lett. 113\, 052601 (2014).\n[3] L. Corradi \, G. Pollarolo\, and S. Szilner\, J. Phys. G: Nucl. Part. Phys. 36\, 1131 01 (2009).\n[4] D. Montanari et al.\, Phys. Rev. C 834\, 137477 (2022).\n[ 5] L. Corradi et al.\, Phys. Lett. B 93\, 054623 (2016).\n[6] B.D. Josephs on\, Phys. Lett. 1\, 251 (1962).\n[7] G. Potel\, F. Barranco\, E. Vigezzi\ , and R. A. Broglia\, Phys. Rev. C 103\, L021601 (2021).\n\nhttps://indico .ific.uv.es/event/7332/contributions/23758/ LOCATION:ADEIT - Valencia URL:https://indico.ific.uv.es/event/7332/contributions/23758/ END:VEVENT END:VCALENDAR