Evidence for a πη-P-wave in p̄p-annihilations at rest into π0π0η

A partial wave analysis is presented of two high-statistics data samples of protonium annihilation into π0π0η in liquid and 12 atm gaseous hydrogen. The contributions from the 1S0 ,3P1 and 3P2 initial atomic fine structure states to the two data sets are different. The change of their fractional contributions when going from liquid to gaseous H2 as calculated in a cascade model is imposed in fitting the data. Thus the uncertainty in the fraction of S-state and P-state capture is minimized. Both data sets allow a description with a common set of resonances and resonance parameters. The inclusion of a πη P-wave in the fit gives supportive evidence for the ρ̂(1405), with parameters compatible with previous findings.