Experimental determination of the kinetic energy distribution of π−p atoms in liquid hydrogen

Abstract We have investigated the kinetic energy distribution of π − p atoms in liquid hydrogen by measuring the Doppler broadening of neutron time-of-flight spectra from the reaction π − p → π 0 n . The existence of “high energy” (⪢1eV) components, containing about half of the π − p atoms, is confirmed and evidence for discrete peaks with energies up to ⋍200eV is found.