J. B. Kopelman

Pi-rho mass spectrum in π−p interactions at 6.7 GeV/c; Spin-parity analyses for A(1200) and for A(1300)

Abstract The rho-pion mass spectrum for negative, positive and zero charge has been evaluated in 6.7 GeV/ c π − proton interactions. The enhancement at 1100 MeV is present but is not strongly produced. The A(1300) is produced at a level of 40% above background. Spin-parity as determined by analysis of events in the negative charge state is consistent with 2 + , but other assignments, for example 1 + or 2 − , cannot be excluded. Spin-parity analyses separately on events in the upper and lower halves of the A(1300) peak give identical results. The A(1200) is produced at a level of 30% above background. Spin-parity analysis prefers exclusion of 0 − and 2 + .

Evidence for narrow 3π effects near 960 MeV in K − P interaction at 4.6 and 5.0 GeV/c☆

Abstract In an investigation of the final states K − π − π + π O p and K − π − π + π + n produced in K − p interactions at 4.6 and 5.0 GeV/ c we have observed narrow enhancements near 960 MeV in both the π + π − π O and π + π + π − distributions. These structures are strongly associated with the Δ(1236). Also, there is evidence for a possible ϱπ decay for these effects.