Observation on pp → 3π°, 2π°η° at rest☆

Abstract Annihilations have been observed of anti-protons stopped in liquid hydrogen yielding 3 π ° and 3 π ° η °, with a ratio 3 π °: 2 π ° η ° of 0.81 ± 0.08. The Dalitz plot of 2100 3 π °-events exhibits structures somewhat similar to those observed in p n →2π − π + (at rest); viz: depopulation at the center, enhancement at small M 2 (2 π °) and at about 2.35 (GeV/ c 2 ) 2 .