Angular distribution measurements of pion single charge exchange in deuterium and hydrogen

Angular distributions of both the d(π-,π0)nn and p(π-,π0)n reactions covering θπ0lab =0 degrees - 150 degrees have been measured at incident pion energies of 164, 263, and 371 MeV. No previous measurements of the deuterium SCX cross section exist between 164 MeV and 500 MeV. These new data will aid the authors in finding evidence for modification of the SCX process beyond the impulse approximation in this simple three body system. This is the first experiment to use the newly build Neutral Meson Spectrometer at LAMPF. The authors used one open-quotes crateclose quotes of 60 CsI crystals to detect both photons from the π0 decay, without the benefit of any converters or tracking wire chambers. The acceptance of the detector was calculated using the EGS code to model the electromagnetic shower process. The luminosity was measured by counting the incoming π- flux (∼3x105 per second, instantaneous) with a set of in-beam scintillators and by using a set of well-understood solid targets of CH2, CD2, and C, providing a reliable normalization. Preliminary results will be shown