Octupole transitions in the 208Pb region

[摘要] The208Pb region is characterised by the existence of collective octupole states. Here we populated such states in208Pb +208Pb deep-inelastic reactions. γ-ray angular distribution measurements were used to infer the octupole character of several E3 transitions. The octupole character of the 2318 keV 17-14+in208Pb, 2485 keV 19/2-13/2+in207Pb, 2419 keV 15/2-9/2+in209Pb and 2465 keV 17/2+11/2-in207Tl transitions was demonstrated for the first time. In addition, shell model calculations were performed using two different sets of two-body matrix elements. Their predictions were compared with emphasis on collective octupole states.

[发布机构] Department of Physics, University of Surrey, Guildford; GU2 7XH, United Kingdom^1;Michigan State University, East Lansing; MI; 48824-1321, United States^2;GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt; D-64291, Germany^3;Physics Division, Argonne National Laboratory, Argonne; IL; 60439, United States^4;Department of Chemistry and Biochemistry, University of Maryland, College Park; MD; 20742, United States^5;H. Niewodniczaski Institute of Nuclear Physics, Kraków; PL-31342, Poland^6;Department of Physics, University of Massachusetts Lowell, Lowell; MA; 01854, United States^7;Department of Physics, Indian Institute of Technology Roorkee, Roorkee; 247667, India^8;Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra; ACT; 0200, Australia; (10) Nuclear Engineering Division, Argonne National Laboratory, Argonne; IL; 60439, United States; (11) National Physical Laboratory, Hampton Road, Middlesex, Teddington; TW11 0LW, United Kingdom; (12) School of Computing, Engineering and Mathematics, University of Brighton, Brighton; BN2 4GL, United Kingdom^9

[关键词] Angular distribution measurements;Matrix elements;Octupole transition;Shell models