Gamow–Teller transitions and neutron–proton-pair transfer reactions

Journal Article · 14 March 2018 · Physics Letters. B

DOI: https://doi.org/10.1016/j.physletb.2018.03.034 · OSTI ID:1426825

Van Isacker, P.  ^[1]; Macchiavelli, A. O. ^[2]

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1. CEA/DRF-CNRS/IN2P3, Caen (France)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

We propose a schematic model of nucleons moving in spin–orbit partner levels, j = l ± 1/2, to explain Gamow–Teller and two-nucleon transfer data in N = Z nuclei above ⁴⁰Ca. Use of the LS coupling scheme provides a more transparent approach to interpret the structure and reaction data. We apply the model to the analysis of charge-exchange, ⁴²Ca(³He,t)⁴²Sc, and np-transfer, ⁴⁰Ca(³He,p)⁴²Sc, reactions data to define the elementary modes of excitation in terms of both isovector and isoscalar pairs, whose properties can be determined by adjusting the parameters of the model (spin–orbit splitting, isovector pairing strength and quadrupole matrix element) to the available data. The overall agreement with experiment suggests that the approach captures the main physics ingredients and provides the basis for a boson approximation that can be extended to heavier nuclei. Lastly, our analysis also reveals that the SU(4)-symmetry limit is not realized in ⁴²Sc.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: AC02-05CH11231; FG02-10ER41700
• OSTI ID: 1426825
• Alternate ID(s): OSTI ID: 1462000
• Journal Information: Physics Letters. B, Vol. 780, Issue C; Related Information: © 2018 The Authors; ISSN 0370-2693
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English