Shape Coexistence at Zero Spin in $^{64}\mathrm{Ni}$ Driven by the Monopole Tensor Interaction

N. Mărginean , D. Little , Y. Tsunoda , S. Leoni , R.V.F. Janssens , B. Fornal , T. Otsuka , C. Michelagnoli (1) , L. Stan , F.C.L. Crespi , C. Costache , R. Lica , M. Sferrazza , A. Turturica , A.D. Ayangeakaa , K. Auranen , M. Barani (1) , P.C. Bender , S. Bottoni , M. Boromiza , A. Bracco , S. Călinescu , C.M. Campbell , M.P. Carpenter , P. Chowdhury , M. Ciemała , N. Cieplicka-Ory `nczak , D. Cline , C. Clisu , H.L. Crawford , I.E. Dinescu , J. Dudouet (2) , D. Filipescu , N. Florea , A.M. Forney , S. Fracassetti , A. Gade , I. Gheorghe , A.B. Hayes , I. Harca , J. Henderson , A. Ionescu , Ł.W. Iskra , M. Jentschel (1) , F. Kandzia (1) , Y.H. Kim (1) , F.G. Kondev , G. Korschinek , U. Köster (1) , M. Krishichayan , M. Krzysiek , T. Lauritsen , J. Li , R. Mărginean , E.A. Maugeri , C. Mihai , R.E. Mihai , A. Mitu , P. Mutti (1) , A. Negret , C.R. Niţă , A. Olăcel , A. Oprea , S. Pascu , C. Petrone , C. Porzio , D. Rhodes , D. Seweryniak , D. Schumann , C. Sotty , S.M. Stolze , R. Şuvăilă , S. Toma , S. Ujeniuc , W.B. Walters , C.Y. Wu , J. Wu , S. Zhu , S. Ziliani

1 ILL - Institut Laue-Langevin
2 IPNL - Institut de Physique Nucléaire de Lyon

The low-spin structure of the semimagic Ni64 nucleus has been considerably expanded: combining four experiments, several 0+ and 2+ excited states were identified below 4.5 MeV, and their properties established. The Monte Carlo shell model accounts for the results and unveils an unexpectedly complex landscape of coexisting shapes: a prolate 0+ excitation is located at a surprisingly high energy (3463 keV), with a collective 2+ state 286 keV above it, the first such observation in Ni isotopes. The evolution in excitation energy of the prolate minimum across the neutron N=40 subshell gap highlights the impact of the monopole interaction and its variation in strength with N.

Mots clés: Nuclear Physics

Domaines: Physique Nucléaire Expérimentale [nucl-ex]; Physique Nucléaire Théorique [nucl-th]

N. Mărginean, D. Little, Y. Tsunoda, S. Leoni, R.V.F. Janssens, et al.. Shape Coexistence at Zero Spin in $^{64}\mathrm{Ni}$ Driven by the Monopole Tensor Interaction. Physical Review Letters, 2020, 125 (10), pp.102502. ⟨10.1103/PhysRevLett.125.102502⟩. ⟨hal-03186279⟩