{sup 193}Hg collective oblate band with E{sub x}>5.7 MeV

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Bulletin of the American Physical Society

OSTI ID:243909

Roy, N; Henry, E A; Becker, J A ^[1]

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1. Lawrence Livermore National Lab., CA (United States); and others

Rotational bands in the neutron-deficient Pb nuclei {sup 192,194,196-201}Pb have been reported recently. Band members are connected by L = 1 transitions, with crossover L = 2 transitions observed at the higher {gamma}-ray energies. Regular and irregular patterns of {gamma}-ray energies are observed. Conversion coefficients determined from intensity balance suggest the L = 1 transitions are M1. The bands have generally been interpreted as collective oblate, involving deformation aligned high-j proton configurations such as {pi}(s{sub {1/2}}{sup {minus}2}h{sub 9/2}i{sub 13/2}), and rotation aligned i{sub 13/2}{sup {minus}n} neutrons. Evidence for a similar band in {sup 193}Hg has been obtained. {sup 193}Hg was populated in the reaction {sup 176}Yb({sup 22}Ne,5n) at E{sub i}({sup 22}Ne) = 110 MeV. Reaction {gamma} rays were detected with the Ge detector array HERA. A new `collective` structure was observed with E{sub x}>5.7 MeV. States of the structure extend from I{ge}47/2 to I +10, and they decay with competing dipole and quadrupole transitions. The ratio B(M1)/B(E2), {approximately} 2{mu}{sup 2}/(e b){sup 2}, is approximately 10x lower in {sup 193}Hg than in the Pb bands. The lowest member is produced with {approximately}20% of the {sup 193}Hg cross section. Evidence for a similar band in {sup 196}Hg will be presented at this meeting.

• OSTI ID: 243909
• Report Number(s): CONF-9304297--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 2 Vol. 38; ISSN BAPSA6; ISSN 0003-0503
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COLLECTIVE EXCITATIONS
DEFORMED NUCLEI
M1-TRANSITIONS
MERCURY 193
MERCURY 196