Footprints of a Broad $\sigma$(600) in Weak-Interaction Processes
  We explore how chiral-symmetry constraints on weak-interaction matrix elements suggest the existence of an intermediate state sigma in several different weak-interaction processes. Particular attention is directed toward recent evidence for a sigma within three-body nonleptonic weak decays. 
V. Elias, A.D. Polosa, M.D. Scadron and N.A. T\"ornqvist