Abstract
Calculations are presented for four relatively strong first-forbidden β decays in the region A=11–16 in order to study the very large mesonic-exchange-current enhancement of the rank-zero components. The capture on is considered on the same footing. The wave functions utilized include up to 4ħω excitations. Two-body exchange-current matrix elements are calculated as well as one-body impulse-approximation matrix elements. The resultant enhancement factor that multiplies the impulse-approximation axial-charge matrix element is thereby determined by comparison to experiment to be =1.61±0.03 from three decays and capture on , which is in excellent agreement with meson-exchange calculations in the soft-pion approximation.
- Received 30 August 1993
DOI:https://doi.org/10.1103/PhysRevC.49.824
©1994 American Physical Society