Positive Pion Production By Negative Pions Thesis PDF Download

A liquid hydrogen target was bombarded by negatitve pions of energies 260, 317, 371, and 427 Mev. Positive pi mesons from the reaction pi /sup -/ + p yields pi /sup +/ + pi /sup -/+ n were detected by using a counter telescope which selected the pi /sup +/ by its characteristic pi - mu decay. With the 260-Mev beam pi /sup +/ mesons were counted at 90 deg in the laboratory system. At 317, 371, and 427 Mev the differential cross section was measured for pi /sup +/ mesons emitted at 60, 90, 125, and 160 deg in the barycentric system. The angular distributions are nearly isotropic at 317 and 371 Mev but are peaked foward at 67 Mev. The total cross sections are: 0.14 plus or minus 0.10 mb at 260 Mev; 0.71 plus or minus 0.17 mb at 317 Mev; 1.93 plus or minus 0.37 mb at 371 Mev; and 3.36 plus or minus 0.74 mb at 427 Mev. These results indicate a much larger cross section than the theoretical prediction based on the static model. Reasonable agreement can be obtained by the inclusion of a pion-pion interaction in the production mechanism. (auth).