Study of antiproton annihilation at rest in liquid and gaseous hydrogen into three neutral pseudoscalar mesons

All-neutral data have been taken with the Crystal Barrel Detector at LEAR/CERN providing high-statistics data samples of protonium annihilation in gaseous hydrogen at 12 atmospheres. The six-photon final state has been selected in order to yield data sets on π0π0π0, π0π0η and π0ηη comparable in statistics to data of antiproton annihilation in liquid hydrogen from former run periods. Production of scalar resonances is favoured in liquid hydrogen where annihilation from initial S-state dominates. In gaseous hydrogen a larger amount of initial P-state annihilation contributes to the final states. Data are presented and preliminary results of partial wave analyses and the ratio of S- versus P-state annihilation rates are given. (orig.)