Observation of the Charge Symmetry Breaking d + d -> 4He + pi0 Reaction Near Threshold

We report the first observation of the charge symmetry breaking d + d -> 4He

• pi0 reaction near threshold at the Indiana University Cyclotron Facility. Kinematic reconstruction permitted the separation of 4He + pi0 events from double radiative capture 4He + gamma + gamma events. We measured total cross sections for neutron pion production of 12.7 ± 2.2 pb at 228.5 MeV and 15.1 ± 3.1 pb at 231.8 MeV. The uncertainty is dominated by statistical errors.