Bohr's symmetry method is applied to an unstable spin- state , which is produced in a reaction and then decays according to . Particles , , , are assumed to be spinless, and is either a spinless particle or a gamma ray. Parity is conserved in production, but not necessarily in decay. The angular distribution of , in the rest system of , is , where and the polar angle is measured from the normal to the production plane. The coefficients depend upon the production angle and upon the dynamics of the production. It is proved here that the sign of the maximum-complexity coefficient depends only upon the parity of , and that the magnitude of is not zero but lies between bounds which depend upon and the parity alone. The implied test for and the parity has the following advantages: (1) The spin is equal to half the largest in . Addition of a small amount of a higher , which always improves the fit, is forbidden by the lower bound of . (2) The bounds of are independent of . Any (perhaps biased) average over may be performed before expanding in the . (3) All the data are condensed into a single test quantity , whose statistical error is reliably known.
- Received 5 September 1963
- Published in the issue dated January 1964
© 1964 The American Physical Society