The Production of Neutrinos and Neutrino Like Particles in Proton - Nucleus Interactions

Abstract

An experimental search was performed to look for the direct production of neutrinos or neutrino-like particles, i.e., neutral particles which interact weakly with hadrons, in proton-nucleus interactions at 400 GeV incident proton energy. Possible sources of such particles include the semi-leptonic decay of new heavy particles such as charm, and the direct production of a light neutral Higgs particle such as the axion. The production of these particles has been inferred in this experiment by energy nonconservation in the collision of a proton with an iron nucleus. The total visible energy of the interaction was measured using a sampling ionization calorimeter. The calorimeter was calibrated with muons. This calibration was adjusted slightly by requiring consistency in the calorimeter shower profile for primary interactions beginning at various depths in the calori- systematic effects in the measurement, the final resolution of the calorimeter was 3.51% and increased with decreasing incident beam energy with a square root dependence on the beam energy'. Energy nonconservation in the data is manifest as a nonGaussian distribution on the low side of the calorimeter measured energy.