Author/Authors :
F.G. Kondev، نويسنده , , M.A. Riley، نويسنده , , R.V.F. Janssens، نويسنده , , J. Simpson، نويسنده , , A.V. Afanasjev، نويسنده , , I. Ragnarsson، نويسنده , , I. Ahmad، نويسنده , , D.J. Blumenthal، نويسنده , , T.B. Brown، نويسنده , , M.P. Carpenter، نويسنده , , P. Fallon ، نويسنده , , S.M. Fischer، نويسنده , , G. Hackman، نويسنده , , D.J. Hartley، نويسنده , , C.A. Kalfas، نويسنده , , T.L. Khoo، نويسنده , , T. Lauritsen، نويسنده , , W.C. Ma، نويسنده , , D. Nisius، نويسنده , , J.F. Sharpey-Schafer، نويسنده , , et al.، نويسنده ,
Abstract :
The highest-spin discrete states (I∼60 ℏ and Ex∼30 MeV) in normal deformed nuclei have been observed in the rare-earth isotope 156Dy using the 124Sn(36S,4n) reaction in conjunction with the GAMMASPHERE spectrometer. The positive parity yrast sequence appears to evolve smoothly from a prolate (collective) towards an oblate (non-collective) shape, in contrast to the sudden shape change observed in the isotone 158Er. Terminating states are identified in the negative parity sequences at Iπ=52− and 53− and specific multi-particle-hole configurations are assigned by comparison with cranked Nilsson-Strutinsky calculations. An order of magnitude increase in the interaction strength between close lying high-spin weakly collective structures is determined compared with that found in the lower-spin strongly collective domain. These results give valuable insight into the interplay between collective and terminating structures, and their competition for yrast status in the 40−60 ℏ spin range.
Keywords :
High-spin collective structures , Band termination , Nilsson-Strutinsky cranking calculations , Bands interaction
