Pion--nucleon interaction and mesonic atoms. Progress report, February 1, 1976--January 31, 1977

During the year February 1, 1976 to January 31, 1977, the major activities under task A have been completion of all equipment and programs necessary for operating Experiment No. 99, measurement of the cross section for π- + p → π- + π+ + n near threshold, operation of Experiment No. 99, preliminary analysis of the data gathered, and preparation of a proposal for an exploratory measurement of π+ and π- double charge exchange in the disintegration of 16O, 40Ca, and 208Pb. The initial, rough analysis of all data in Experiment No. 99 should be completed by the end of the contract year and will yield a total cross section for pion production at 6 energies between 225 and 350 MeV with 10 percent accuracy. In addition, the doubly differential cross section will be far more detailed than has previously been available at these energies. During the year February 1, 1976 to January 31, 1977, research under Task B, Mesonic Atoms, has included collection and analysis of muonic atom data at LAMPF, feasibility studies for a further beam in the stopped muon channel at LAMPF, analysis of antiprotonic atom data collected at BNL, and collection of data on the antiproton-hydrogen system at BNL. A list of publications is included