Identification of excited states in the T{sub z}=+(1)/(2) nucleus {sup 75}Rb: The quest for experimental signatures of collective neutron-proton correlations

Journal Article · Fri Aug 01 00:00:00 EDT 1997 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.56.R591· OSTI ID:528205

Gross, C J; Rudolph, D; Baktash, C; Cullen, D M; Garrett, J D ^[1]; Gross, C J ^[2]; Rudolph, D; Harder, A; Kabadiyski, M K; Lieb, K P ^[3]; Satula, W; Sheikh, J A ^[4]; Satula, W ^[5]; Alexander, J; Coleman-Smith, P J; Cunningham, R A; Lazarus, I; Simpson, J; Warner, D D ^[6]; Gelletly, W ^[7] ; Roth, H A; Skeppstedt, O ^[8]; Sarantites, D G ^[9]; Varley, B J ^[10]

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1. Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6371 (United States)
2. Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37831 (United States)
3. II. Physikalisches Institut, Universitaet Goettingen, D-37073 Goettingen (Germany)
4. Joint Institute for Heavy Ion Research, Oak Ridge, Tennessee 37831-6374 (United States)
5. Department of Physics, University of Tennessee, Knoxville, Tennessee 37996 (United States)
6. CCLRC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom)
7. Physics Department, University of Surrey, Guildford GU2 5XH (United Kingdom)
8. Department of Physics, Chalmers University of Technology, S-412 96 Goeteborg (Sweden)
9. Department of Chemistry, Washington University, Saint Louis, Missouri 63130 (United States)
10. Schuster Laboratory, University of Manchester, Manchester M13 9PL (United Kingdom)

Excited states in the T{sub z}=(1)/(2) nucleus {sup 75}Rb were observed for the first time using the {sup 40}Ca({sup 40}Ca,{alpha}p) reaction at 128 MeV. Identification was achieved using events detected by the Daresbury recoil separator in coincidence with {gamma} rays detected in the 45 element EUROGAM I Ge-detector array. Threefold events were used to build a decay scheme which consists of two rotational bands observed to I{sup {pi}}=((45)/(2){sup +}) and I{sup {pi}}=((33)/(2){sup {minus}}). The positive parity band in {sup 75}Rb behaves similarly to a negative-parity band in {sup 74}Kr and contains a region of alignment at {h_bar}{omega}{approx}0.75 MeV. These data, and those of {sup 77}Sr, can be interpreted by treating protons and neutrons separately in a cranked shell model approach despite a recent suggestion for the presence of T=1 neutron-proton pairing correlations in the neighboring self-conjugate, odd-odd {sup 74}Rb ground state band. Our study suggests that some experimental observables such as the energy levels and moments of inertia, may not be able to differentiate between different T=1 pairing phases in these T{sub z}=(1)/(2) nuclei. {copyright} {ital 1997} {ital The American Physical Society}

• Research Organization: Oak Ridge Institute of Science and Education
• DOE Contract Number: AC05-76OR00033; AC05-96OR22464; FG02-88ER40406; FG02-91ER40609; FG02-96ER40963; FG05-87ER40361; FG05-93ER40770
• OSTI ID: 528205
• Journal Information: Physical Review, C, Vol. 56, Issue 2; Other Information: PBD: Aug 1997
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
RUBIDIUM 75
EXCITED STATES
CALCIUM 40 TARGET
CALCIUM 40 REACTIONS
PARTICLE IDENTIFICATION
PROTON-NEUTRON INTERACTIONS
CORRELATIONS
ROTATIONAL STATES
ALIGNMENT
ENERGY LEVELS
MOMENT OF INERTIA