Elementary particle interactions: Progress report, October 1, 1985-September 30, 1986

It has been found that in photoproduction, where Deck effects are minimal, the A1 mass and width is similar to that of the A2, in direct contradiction to electron-positron collider results indicating a considerably lower A1 mass. The reaction γp → p(ωπ0) at 20 GeV with a decay angular distribution study of the (ωπ0) state has been analyzed to demonstrate its consistency with the B(1235) J/sup P/ = 1+. Practical high resolution holographic photography of a large bubble chamber volume was demonstrated to be achievable with efficiencies greater than 25%, giving strong support to the technical feasibility of the tau neutrino experiment. It has been decided to construct the SLD luminosity monitor using silicon diode technology, and to construct a lead liquid argon calorimeter (instead of uranium)