Abstract
We have measured the mean lifetime of the first excited state of at 0.72 Mev as 1.05±0.10 mμsec by bombarding with pulsed beams of 3-Mev protons and studying the delayed emission of gamma rays. This figure is a little longer than that given by earlier measurements of the lifetime using recoil methods. The result is compared with preliminary shell model calculations and it is concluded that it is probably inconsistent with those calculations, at least if one restricts oneself to the value of the intermediate coupling parameter that gives good agreement with the experimental level scheme. It seems that some collective motion must be envisaged even in so light a nucleus as .
- Received 25 September 1956
DOI:https://doi.org/10.1103/PhysRev.105.232
©1957 American Physical Society