Study of the Reaction Negative Pion-Proton -- -> Neutron, Lambda, Anti-Lambda at 6.0 and 7.0 Gev/c.

The (LAMDA)(LAMDA) system produced in the reaction (pi)('-)p (--->) n(LAMDA)(LAMDA) at 6.0 and 7.0 GeV/c has been studied utilizing the ANL 1.5 m Streamer Chamber Facility. The trigger required an all neutral final state and the detection of at least two charged particles in a downstream hodoscope. A 400,000 photograph exposure yielded 284 unweighted n(LAMDA)(LAMDA) events. The cross section for the reaction is 0.51 + 0.22 (mu)b at 6.0 GeV/c and 1.21 + .23 (mu)b at 7.0 GeV/c. There is an indication of a possible baryonium state with a mass and width of approximately 2430 MeV and 60 MeV respectively. The structure appears as a 2.5-standard deviation effect in the mass spectrum, and there are correlated effects in the (LAMDA) and (LAMDA) polarizations, the distribution of the Jackson angle, and the (VBAR) t (VBAR) distribution.