On the Possible Existence of Doubly Strange Heavy Mesons

(ricevuto il 12 Dicembre 1959) Recently there have been revived indications (1) of the possible existence of doubly strange heavy mesons of approximately 1500 electron masses. In this note we wish to discuss some of the theoretical implications of ~his. The positive meson to+ (S~ 2) could first be produced by 1.8 GeV/c pions in the reaction (1) r~-+p-~E-+~ +. This process also gives a markedly lower threshold for E production than the conventional one arising from association with two K-mesons. However since all E interactions seem to be anomalously weak (2) perhaps the threshold of greater importance might prove to be that for the reaction (2) =-+p-~A°+K-+¢o +, which occurs at 2.5 GeV/c pion momentum. Just above this at 2.7 GeV/c ~s the first threshold for ~-(S =-2) production , by the process (3) =-q-p-+iV-~-co+q-~-. The mesons find a natural place in a four dimensional classification scheme (8) as the charged members of the (0, 1) triplet. The neutral member (*) ~o would be expected to be highly unstable since it has S=0 and would only manifest itself as an I=½ resonance in pion-nucleon scattering. If the mass were (*) t~esearch supported in part by the (*) It is in requiring the existence of coo (and X °) as well as in the insistence that if co-particles exist, X-particles do so too, that the application of our scheme differs from just filling gaps in the Gell-Mann-Nishijima strangeness assignments.