Shell-structure and pairing interaction in superheavy nuclei; Rotational properties of the =104 nucleus Rf

Greenlees, P. T.*; Rubert, J.*; Piot, J.*; Gall, B. J. P.*; Andersson, L. L.*; Asai, Masato  ; Asfari, Z.*; Cox, D. M.*; Dechery, F.*; Dorvaux, O.*; Grahn, T.*; Hauschild, K.*; Henning, G.*; Herzan, A.*; Herzberg, R.-D.*; Heberger, F. P.*; Jakobsson, U.*; Jones, P.*; Julin, R.*; Juutinen, S.*; Ketelhut, S.*; Khoo, T.-L.*; Leino, M.*; Ljungvall, J.*; Lopez-Martens, A.*; Lozeva, R.*; Nieminen, P.*; Pakarinen, J.*; Papadakis, P.*; Parr, E.*; Peura, P.*; Rahkila, P.*; Rinta-Antila, S.*; Ruotsalainen, P.*; Sandzelius, M.*; Sren, J.*; Scholey, C.*; Seweryniak, D.*; Sorri, J.*; Sulignano, B.*; Theisen, Ch.*; Uusitalo, J.*; Venhart, M.*

Rotational band structure of the =104 nucleus Rf has been observed for the first time using an in-beam -ray spectroscopic technique. This nucleus is the heaviest among the nuclei whose rotational band structure has ever been observed. Thus, the present result provides valuable information on the single-particle shell structure and pairing interaction in the heaviest extreme of nuclei. The deduced moment of inertia indicates that there is no deformed shell gap at =104, which is predicted in a number of current self-consistent mean-field models.