First results from OBELIX on reactions with detected neutral poins in the final state

Summary  We describe some results obtained by the OBELIX experiment at LEAR by exploiting the whole spectrometer, including the electromagnetic calorimeter, to study the antiproton-proton annihilation at rest in an NTP hydrogen target. In particular, we give some information on the calibration of the calorimeter, as obtained from the analysis of two-prong events, and we describe the status of the analysis of the first sample of �all neutrals� events collected in gaseous hydrogen. A preliminary result on the branching ratio of the annihilation reaction $$\bar pp \to \pi ^0 \pi ^0 $$ is reported.