THE SCATTERING OF POSITIVE 120 MEV PIONS ON PROTONS. PART I. PART II

An investigation of the elastic scattering of 120 Mev positive pions by protons is described in which a liquid propane chamber was exposed to the CERN 600 Mev synchrocyclotron. The results refer to 5405 selected events in which the contamination from scattering on carbon nuclei is shown to be negligible. The values obtained for the phase shifts are: alpha /sub 3//sub 1/ = -2.60 deg plus or minus 0.69 deg , alpha /sub 3/= -11.05 deg plus or minus 1.32 deg , alpha /sub 3//sub 3/ = +31.67 deg plus or minus O.O1 deg . The value of alpha /sub 3/ differs significantly from that expected if the linear dependence of alpha /sub 3/ on the momentum, which has been proposed by some authors, is assumed. (auth)