Many-pion production inπ+dreactions at 15 GeV/c

Abstract

The average number of charged pions produced in v'd reactions at 15-GeV/c vf momentum is 3.6+0.1 and the average number of vO's is 1.9 k 0 . 2 . The average number of TO'S produced is essentially independent of the number of charged pions. About 45% of the events have four or more charged pions in the final state. The exclusive final states with four or more charged pions with zero or one v0 are presented and compared with modified phase-space background computations. Other than the well-known resonances, such as the po, no new peaks have been observed. Coherently produced multipion systems with up to seven pions are also discussed. Detailed cross-section information for every final state is presented.