Gamma-Ray Spectroscopy at the Limits: First Observation of Rotational Bands in 255Lr

S. Ketelhut , P.T. Greenlees , D. Ackermann , S. Antalic , E. Clement (1) , I.G. Darby , O. Dorvaux (2) , A. Drouart (1) , S. Eeckhaudt , B.J.P. Gall (2) , A. Gorgen (1) , T. Grahn , C. Gray-Jones , K. Hauschild (3) , R.D. Herzberg , F.P. Hessberger , U. Jakobsson , G.D. Jones , P. Jones , R. Julin , S. Juutinen , T.L. Khoo , W. Korten (1) , M. Leino , A.P. Leppaanen , J. Ljungvall (1) , S. Moon , M. Nyman , A. Obertelli (1) , J. Pakarinen , E. Parr , P. Papadakis , P. Peura , J. Piot (2) , A. Pritchard , P. Rahkila , D. Rostron , P. Ruotsalainen , M. Sandzelius , J. Saren , C. Scholey , J. Sorri , A. Steer , B. Sulignano (1) , C. Theisen (1) , J. Uusitalo , M. Venhart , M. Zielinska , M. Bender (4) , P.H. Heenen

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
2 IPHC - Institut Pluridisciplinaire Hubert Curien
3 CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse
4 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan

The rotational band structure of 255Lr has been investigated using advanced in-beam gamma-ray spectroscopic techniques. To date, 255Lr is the heaviest nucleus to be studied in this manner. One rotational band has been unambiguously observed and strong evidence for a second rotational structure was found. The structures are tentatively assigned to be based on the 1/2;{-}[521] and 7/2;{-}[514] Nilsson states, consistent with assignments from recently obtained alpha decay data. The experimental rotational band dynamic moment of inertia is used to test self-consistent mean-field calculations using the Skyrme SLy4 interaction and a density-dependent pairing force.

Domaines: Physique Nucléaire Théorique [nucl-th]

S. Ketelhut, P.T. Greenlees, D. Ackermann, S. Antalic, E. Clement, et al.. Gamma-Ray Spectroscopy at the Limits: First Observation of Rotational Bands in 255Lr. Physical Review Letters, 2009, 102, pp.212501. ⟨10.1103/PhysRevLett.102.212501⟩. ⟨in2p3-00399512⟩