Lifetimes of low-lying excited states in
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); TRIUMF, Vancouver, BC (Canada)
- Simon Fraser Univ., Burnaby, BC (Canada). Dept. of Chemistry
- TRIUMF, Vancouver, BC (Canada)
- Univ. of Toronto, ON (Canada). Dept. of Physics
- TRIUMF, Vancouver, BC (Canada); Univ. of Surrey, Guildford (United Kingdom). Dept. of Physics
- Univ. of Guelph, ON (Canada). Dept. of Physics
Background: The evolution of nuclear magic numbers at extremes of isospin is a topic at the forefront of contemporary nuclear physics. is a prime example, with increasing experimental data coming to light on potentially doubly magic and at the proton-rich and proton-deficient extremes, respectively; however, experimental discrepancies exist in the data for less exotic systems. Purpose: In the value—a key indicator of shell evolution—has been experimentally determined by two different methodologies, with the results deviating by . Here, we report on a new high-precision measurement of this value, as well as the first measured lifetimes and hence transition strengths for the and states in the nucleus. Methods: The Doppler-shift attenuation method was implemented using the TRIUMF-ISAC -ray escape-suppressed spectrometer (TIGRESS) -ray spectrometer and the TIGRESS integrated plunger device. High-statistics Monte Carlo simulations were utilized to extract lifetimes in accordance with state-of-the-art methodologies. Results: Lifetimes of fs, fs, and fs were extracted. This yields a transition strength for the first-excited state of . Conclusions: Finally, the measured lifetime disagrees with the previous Doppler-shift attenuation method measurement by more than , while agreeing well with a previous value extracted from Coulomb excitation. The newly extracted value indicates a more significant reduction in the isotones approaching .
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); TRIUMF, Vancouver, BC (Canada); Simon Fraser Univ., Burnaby, BC (Canada)
- Sponsoring Organization:
- USDOE; Natural Sciences and Engineering Research Council of Canada (NSERC); The Canada Foundation for Innovation; British Columbia Knowledge Development Fund (Canada); National Research Council (NRC) (Canada)
- Grant/Contract Number:
- AC52-07NA27344
- OSTI ID:
- 1438625
- Alternate ID(s):
- OSTI ID: 1433278
- Report Number(s):
- LLNL-JRNL-744244; TRN: US1900471
- Journal Information:
- Physical Review C, Vol. 97, Issue 4; ISSN 2469-9985
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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