Nondynamical Structure of Particle Reactions Containing Identical Particles

Abstract

That part of the structure of particle reactions of arbitrary spins which is independent of dynamics is investigated in the case when identical particles are contained in the reaction. First, a general discussion of the structure of composite reactions reveals that mirror relations arise naturally in such reactions even when the characteristic quantity contains an even number of letters. It is also shown that there is a close analogy between the constraints of time-reversal invariance and those of identical particles, as applied to their respective self-transforming reactions. It is then easy to determine the changes in the tests of other conservation laws, like parity conservation and time-reversal invariance, in the presence of identical particles. It is found that some tests are erased by the presence of identical particles; others are simplified. With one exception, however, the presence of identical particles does not preclude tests of other symmetries for a reaction. Identical particles also widen the range of self-transforming reactions. Relatively little can be said about reactions with only one pair of identical particles. Two examples illustrate the results in detail.