Coherent states with definite charge and isospin and cluster production

A solvable unitary model of Auerbach et al. is generalized to take into account the isospin structure of the pion and the leading-particle system. The coherent-state representation is used to discuss the production of isovector objects, such as pions and resonances (or clusters). Particular attention is paid to productions when the isospin state of the ingoing and outgoing leading-particle system is fixed. The isospin analysis of the pion-pion correlation is performed by assuming both the direct-pion-emission mechanism and the cluster-emission mechanism. The slope of ${〈n_0〉}_{n_{-}}$ is predicted to increase with energy and is positive in the $\pi -\rho$ and $\rho -B$ regions (about 3/4 and about 14/17, respectively).