Evolution of collectivity in the ⁷⁸Ni region: Coulomb excitation of ⁷⁴Ni at intermediate energies.

¹ INFN Legnaro National Laboratories, Legnaro (Pd), Italy
² Department of Physics, Padua University, Padua, Italy
³ NSCL, Michigan State University, East Lansing, Michigan 48824-1421, USA
⁴ INFN Pisa, Pisa, Italy
⁵ Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
⁶ INFN Naples, Naples, Italy
⁷ Physics Department, Naples University Federico II, Italy
⁸ Physics Department, Deenbandhu Chhoturam University, Murthal, Sonepat, Haryana 131039, India
⁹ Ionizing Radiations Laboratory, University of Salamanca, Spain
¹⁰ INFN Padua, Padua, Italy
¹¹ IFIC, CSIC-University of Valencia, Valencia, Spain

^a e-mail: tommaso.marchi@lnl.infn.it

Published online: 20 March 2014

Abstract

The study of the collective properties of nuclear excitations far from stability provides information about the shell structure at extreme conditions. Spectroscopic observables such as the energy or the transition probabilities of the lowest states, in nuclei with large neutron excess, allow to probe the density and isospin dependence of the effective interaction. Indeed, it was recently shown that tensor and three-body forces play an important role in breaking and creating magic numbers. Emblematic is the case of the evolution of the Ni isotopic chain where several features showed up moving from the most neutron rich stable isotope (⁶⁴Ni) towards the ⁷⁸Ni nucleus where the large neutron excess coincides with a double shell closure. In this framework, we have recently performed an experiment with the goal to extract the B(E2; 0⁺ → 2⁺) value for the ⁷⁴Ni nucleus in an intermediate-energy Coulomb excitation experiment: preliminary results are discussed.