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Nanosecond isomers and the evolution of collectivity in stable, even-A Hg isotopes

Journal Article · · Physical Review. C
 [1];  [2];  [3];  [3];  [3];  [4];  [5];  [6];  [6];  [6];  [6];  [7];  [6];  [8]
  1. Univ. of Mumbai (India); Univ of NC - Chapel Hill and TUNL
  2. Univ. of Mumbai (India); Univ. of Massachusetts, Lowell, MA (United States)
  3. Univ. of Mumbai (India)
  4. Univ. of Massachusetts, Lowell, MA (United States)
  5. Univ. of North Carolina, Chapel Hill, NC (United States); Duke Univ., Durham, NC (United States)
  6. Argonne National Lab. (ANL), Argonne, IL (United States)
  7. Univ. of Massachusetts, Lowell, MA (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
  8. Argonne National Lab. (ANL), Argonne, IL (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
Isomeric states and associated collective structures have been studied up to high spin in 198,200,202Hg using multinucleon transfer reactions and the Gammasphere array. A coupled rotational band, with possible four-quasiparticle character, is established in 198Hg. Sequences built on two-quasiparticle, positive- and negative-parity levels are assigned to 202Hg. New isomers in 202Hg with Iπ = (7) and (9), and T1/2 = 10.4(4) ns and 1.4(3) ns, respectively, have been identified. A half-life of 1.0(3) ns is established for the Iπ = 12+ state in 200Hg. B(E2) values deduced from isomeric transitions in Hg isotopes indicate that, while collectivity near the ground state gradually diminishes from N = 112 to N = 124, it is found to increase for the 12+ and 9 states up to N = 118, followed by a reduction for higher neutron numbers. Calculations using the ultimate cranker code provide insight into the variation of deformation with spin and allow for an understanding of observed band crossings. As a result, the evolution of collectivity with spin, and along the isotopic chain, is described.
Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States). Argonne Tandem Linac Accelerator System (ATLAS); Univ. of North Carolina, Chapel Hill, NC (United States)
Sponsoring Organization:
Government of India; USDOE Office of Science (SC), Nuclear Physics (NP); University Grants Commission
Grant/Contract Number:
AC02-06CH11357; FG02-94ER40834; FG02-94ER40848; FG02-97ER41033; FG02-97ER41041
OSTI ID:
1764062
Alternate ID(s):
OSTI ID: 1774510
Journal Information:
Physical Review. C, Journal Name: Physical Review. C Journal Issue: 1 Vol. 103; ISSN 2469-9985
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

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