Neutron–proton pairing competition in N = Z nuclei: Metastable state decays in the proton dripline nuclei NB-82(41) and Tc-86(43)

A.B. Garnsworthy A , P.H. Regan , L. Cáceres , S. Piétri , Y. Sun , D. Rudolph , M. Górska , Zs. Podolyák , S.J. Steer , R. Hoischen , A. Heinz , F. Becker , P. Bednarczyk , P. Doornenbal , H. Geissel , J. Gerl , H. Grawe , J. Grebosz , A. Kelic , I. Kojouharov , N. Kurz , F. Montes , W. Prokopowicz , T. Saito , H. Schaffner , S. Tachenov , E. Werner-Malento , H.J. Wollersheim , G. Benzoni , Bertram Blank (1) , C. Brandau , A.M. Bruce , F. Camera , W.N. Catforda , I.J. Cullen , Zs. Dombrádi , E. Estevez , W. Gelletly , G. Ilie , J. Jolie , G.A. Jones , A. Jungclaus , M. Kmiecik , F.G. Kondev , T. Kurtukian Nieto (1, 2) , S. Lalkovski , Z. Liu , A. Maj , S. Myalski , M. Pfützner , S. Schwertel , T. Shizuma , A.J. Simons , P.M. Walker , O. Wielandi , F.R. Xu

1 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
2 USC - Universidade de Santiago de Compostela [Spain]

The low-lying structures of the self-conjugate (N = Z) nuclei Nb-82(41)41 andTc-86(43)43 have been investigated using isomeric-decay spectroscopy following the projectile fragmentation of a Ag-107 beam. These represent the heaviest odd–odd N = Z nuclei in which internal decays have been identified to date. The resulting level schemes shed light on the shape evolution along the N = Z line between the doubly-magic systems Ni-56(28) and Sn-100(50) and support a preference for T = 1 states in Tz = 0 odd–odd nuclei at low excitation energies associated with a T = 1 neutron–proton pairing gap. Comparison with Projected Shell Model calculations suggests that the decay in Nb-82 may be interpreted as an isospin-changing K isomer.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

A.B. Garnsworthy A, P.H. Regan, L. Cáceres, S. Piétri, Y. Sun, et al.. Neutron–proton pairing competition in N = Z nuclei: Metastable state decays in the proton dripline nuclei NB-82(41) and Tc-86(43). Physics Letters B, 2008, 660, pp.326-330. ⟨10.1016/j.physletb.2008.01.017⟩. ⟨in2p3-00290042⟩