Coherent pion production in 12C(p, nπ) at 800 MeV

Studies of the production of the Δ resonance in hadronic charge exchange reactions show a shift in the Δ peak position. Measurements looking also at the Δ decay products give some evidence for coherent pion production. We have recently completed a new measurement of the 12 C ( p , n ) reaction leading to the Δ resonance, including a higher resolution coincidence measurement of decay π's in the forward direction. We describe the experiment and some aspects of the preliminary analysis.