Abstract
The beta decay of to bound states of has been investigated by observation of the beta-ray and gamma-ray spectra with scintillation spectrometers. A gas target of was bombarded with 2-MeV tritons from an electrostatic generator to yield 4.2-sec by the reaction . Gamma rays of 0.87 and 2.19 MeV were observed, corresponding to beta transitions to the 0.87- and 3.06-MeV levels in . Analysis of the beta-ray spectrum indicated the presence of a beta-decay branch to the ground state of . The branching fractions and values for these three beta transitions are: g.s.—1.6%, ; 0.87-MeV level—2.6%, ; and 3.06-MeV level—0.5%, . Uncertainties in these values are about ±0.1. The large value for the allowed transition to the 3.06-MeV state lends support to previous theoretical calculations which indicate that this low-lying negative parity state in consists of a three-particle excitation of the core.
- Received 15 November 1963
DOI:https://doi.org/10.1103/PhysRev.134.B16
©1964 American Physical Society