Abstract
Photon spectra from radiative capture of stopped negative pions captured by and nuclei have been measured with a high resolution pair spectrometer. In the bound region transitions have been observed to (g.s.), (3.5 MeV), (g.s.), (4.9 MeV), and (6.3 MeV). In addition, strong transitions to narrow states above the neutron separation threshold were observed in both cases. The results for are in agreement with detailed shell model calculations of this process. Major strength is observed for states formed by coupling extra nucleons or holes to the spin-quadrupole and , states in . The branching ratio is shown to be consistent with beta decay and electroexcitation data, through a combined phenomenological analysis. The observed transition strengths are accounted for by matrix elements of the spin-density operators and .
NUCLEAR REACTIONS , ; measured normalized ; deduced upper limit on for →(g.s.) at MeV/c, systematics of SIGDR in . Stopped ; pair spectrometer; 850 keV at 129.4 MeV.
- Received 6 December 1982
DOI:https://doi.org/10.1103/PhysRevC.27.1621
©1983 American Physical Society