COHERENT DISSOCIATION O-16-]4-ALPHA IN PHOTOEMULSION AT AN INCIDENT MOMENTUM OF 4.5 GEV C PER NUCLEON/

First searches for the coherent dissociation of relativistic oxygen nu clei into four alpha particles are reported. It is shown that reaction s of this type are characterized by a significantly lower decay temper ature than the conventional multifragmentation of residual projectile nuclei. The momentum spectra and correlations of alpha particles are n ot reproduced by the simple statistical model of direct fragmentation. The possibility that the oxygen nucleus undergoing fragmentation acqu ires a nonzero angular momentum in the collision process is discussed.