Oblate L = 1 bands in {sup 194,196-201}Pb, and {sup 193}Hg

Conference · Sun Nov 01 04:00:00 EST 1992

OSTI ID:10105936

Becker, J A; Kuhnert, A; Stoyer, M A; Brinkman, M J; Wang, T F; Roy, N ^[1]; Cizewski, J A ^[2]; Stephens, F S; Deleplanque, M A; Diamond, R M; Azaiez, F; Macchiavelli, A O; Korten, W ^[3]; Draper, J E ^[3]

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1. Lawrence Livermore National Lab., CA (United States)
2. Rutgers--the State Univ., New Brunswick, NJ (United States)
3. Lawrence Berkeley Lab., CA (United States)

Reports of recent experiments have included observations of regular and irregular bands in neutron deficient Pb isotopes with A=194, 196--201. The bands are populated strongly in HI,xn reactions. The shared characteristics of the bands include: (1) Bandhead energies of few MeV; (2) High bandhead spin; (3) Large alignments; (4) Small dynamic moments of inertia, and (5) Strong L = 1 transitions and weaker L = 2 crossover transitions, with B(Ml/B(E2)) {approx} 20 {mu}{sup 2}/e{sup 2}b{sup 2}. Lifetimes of band members in the {sup 198}Pb regular band are B(Ml) {approx} 1 W.u., and B(E2) {approx} 10 W.u. (with large errors). These observations are consistent with an interpretation of the regular structures as collective oblate bands with both proton and neutron excitations involved; the closed proton shell at Z = 82 is broken, and coupled to v(i{sub l3/2}){sup {minus}n} excitations. The irregular structures may correspond to triaxial shapes, with similar orbits involved. A similar structure has been also found in {sup 193}Hg.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48; AC03-76SF00098
• OSTI ID: 10105936
• Report Number(s): UCRL-JC--111939; CONF-921116--12; ON: DE93003467
• Country of Publication: United States
• Language: English

Related Subjects

663110
663580
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
A = 190-219
ENERGY-LEVEL TRANSITIONS
GENERAL AND AVERAGE PROPERTIES OF NUCLEI AND NUCLEAR ENERGY LEVELS
LEAD ISOTOPES
LIFETIME
M1-TRANSITIONS
MERCURY 193
MOMENT OF INERTIA
NUCLEAR STRUCTURE