A study of the centrally produced ?+???0 system formed in the reactionpp?p f (?+???0)p s at 300 GeV/c

The reactionpp→p f (π+π−π0)p s , where the π+π−π0 system is centrally produced, has been studied at 300 GeV/c. The π+π−π0 mass spectrum shows evidence for the η, ω anda 2 (1320) as well as an enhancement in thea 1 (1260) region. A Dalitz plot analysis of the π+π−π0 system has been performed. Thea 1 (1260) parameters coming from the fit of the 1+ S wave arem=1208±15 MeV and Γ=430±50 MeV. No evidence is found for theh 1(1170) orh 1(1380).