K-meson semileptonic and nonleptonic decays in the statistical quark model

Abstract

The statistical quark model for fireball decay (1) can be extended to multiparticle production processes involving also electromagnetic or weak interactions. For instance, electromagnetic lepton pair production was considered in (2) and the multihadron characteristics of the weak decays of hypothetical charmed mesons were calculated in (3). The model is based on a statistical emission chain. I t was originally proposed for processes with a large number of pions (i.e. fireballs in the statistical bootstrap model (4,5)) when quantum interference effects are presumably not very important. In semileptonic and noulcptonic weak decays of metastable hadrons, however, also few-body channels are essential therefore the correct quantum treatment of interferences, e.g. the correct internal quantum number structure is important. A prescription for imposing S U3 quantum number conservation in the statistical quark model was given in ref. (6,7). In what follows the statistical quark model will be applied to K-meson decays. Due to the limited phase space only 1, 2 or 3 pions are emitted and the decay amplitudes cannot change very much within the physical region. Therefore we shall assume