Research program in experimental high energy physics. Progress report, 1 January-31 December 1986

During the past year, analysis has continued on the data of SLAC experiments BC72/73/75, studying the interactions in hydrogen of 20 GeV polarized photons. Results have been obtained on photoproduction of charm and on the lifetimes of charmed particles, and inclusive γp interactions are being studied in detail in this high statistics sample. The hybrid detector built by the Tau Neutrino Collaboration, with a Tohoku one-meter holographic freon bubble chamber as target, has had a successful first run at the Tevatron (E745), and data obtained on muon neutrino interactions at high energies are being analyzed. The system is being upgraded for a second phase of running in the Tevatron muon neutrino beam and for eventual use with the Direct Neutral Lepton Facility, in a search for direct observation of tau neutrino interactions (E636) if and when this facility becomes available. Meanwhile, analysis of data on some aspects of interactions of hadrons with protons and heavier nuclei is continuing (Fermilab E565, E570, E E154). Monte Carlo studies of various calorimeter designs have been carried out, with a view to finding ways to employ absorber materials other than uranium effectively, by making use of a software technique to substitute for the compensating effect of uranium. The technique will be investigated in an experiment at CERN whose aim is to test this procedure for the HERA H-1 calorimeter. The group at Brown has joined a collaboration to carry out experiments in high energy physics, with relevance to cosmic rays and astrophysics, in the new underground laboratory being prepared at Gran Sasso. This collaboration will build a detector (LVD) which includes a large volume of liquid scintillator together with a multilayered omnidirectional tracking system of high angular resolution