Study of the I = 12 pππ system in 10 GeV/c K+p interactions

We have studied the peripherally-produced pπ+π− system from the reaction K+p → K+p π+π− for pπ+π− masses less than 1.9 GeV/c2. Analysis of the angular distributions of the normal to the pππ decay plane and a model-dependent analysis of the Dalitz plot and decay angular distributions both show that more than one spin-parity state is present throughout the region. For pπ+π− masses less than 1.5 GeV/c2 JP in the Δπ system is predominantly 3−2 while above 1.6 GeV/c JP = 52+ and 12+ are both significant while there is a substantial non-Δπ contribution at all masses. None of our Δπ amplitudes show clearly defined resonant behaviour.