High-energy physics progress report, October 1, 1974--September 30, 1975

Major efforts of the ERDA-sponsored high-energy group at the University of Massachusetts went toward advancement of programs at the Multi-Particle Spectrometer (MPS) at Brookhaven National Laboratory. Several sequences of tests took place during the past year in which a large water Cherenkov counter developed by U. Mass. was demonstrated to respond with better than 99 percent efficiency on minimum-ionizing particles and to give near-zero signals on slow protons. This counter was utilized as a primary component of a trigger in a counter/spark-chamber experiment to study high-mass K*'s; this constituted the first full-fledged MPS experiment since the general MPS search for ''Charm,'' which took place from late 1974 to April of 1975. The U. Mass. large time-of-flight (TOF) counter system was developed further; pulse height and time resolution looked excellent in testing alongside the MPS. The entire TOF mechanical structure is complete, and most of the electronics is nearing completion. The polarized target development is nearly finished; and installation of the target for testing at the MPS is anticipated in the near future. Financial support has been given to efforts of other faculty who spent approximately four months at Cornell in studies of proton Compton scattering