Search for the 1/2_2 intruder bandhead in 35P

ORAL

Abstract

Particle-hole sd-pf cross-shell intruder configurations have been observed in the low-lying level scheme of N = 20 even-even nuclei near the Island of Inversion centered around 32Mg. However, the expected 1/2_2 intruder bandhead has not yet been identified in the odd-even nucleus 35P. Previous attempts to identify this state suffered from a large background in the region of interest arising from contaminants in the target.

We will report on a recent measurement using the 36S(d, 3He)35P reaction in inverse kinematics with the Helical Orbit Spectrometer (HELIOS) at ATLAS (ANL). Thanks to the unique capabilities of HELIOS, enhanced with a recoil detector setup, it is possible to perform the reaction in nearly background free conditions.

An analysis of the reconstructed 3He spectrum in HELIOS did not show a peak that could be associated with the 1/2_2 intruder state in the region of interest with an intensity greater than 5% of the ground-state. This result provides an additional constraint to state-of-the-art theoretical descriptions to further understand the evolution of shell structure in the region.

*This research was funded by LBNL-LDRD (LDRD NS16-128), and by the DOE (DE-AC02-05CH11231 and DE-AC02-06CH11357). It used ANL’s ATLAS facility, which is a DOE User Facility.

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Presenters

  • Marco Salathe

    • Nuclear Science Division, Lawrence Berkeley National Laboratory
    • Lawrence Berkeley Natl Lab

Authors

  • Marco Salathe

    • Nuclear Science Division, Lawrence Berkeley National Laboratory
    • Lawrence Berkeley Natl Lab

  • Heather Crawford

    • Nuclear Science Division, Lawrence Berkeley National Laboratory
    • Lawrence Berkeley Natl Lab
    • Lawrence Berkeley Natl Lab, Argonne Natl Lab, Los Alamos Natl Lab, University of Connecticut, iThemba LABS, University of Maryland
    • Lawrence Berkeley National Laboratory