Neutral current coherent pion production

We investigate the neutrino induced coherent pion production reaction at low and intermediate energies. The model includes pion, nucleon, and Δ(1232) as the relevant hadronic degrees of freedom. Nuclear medium effects on the production mechanisms and pion distortion are taken into account. We find that the dominance of the Δ excitation holds due to large cancellations among the background contributions. We consider two sets of vector and axial-vector N-Δ transition form factors, evidencing the strong sensitivity of the results to the axial coupling C5A(0). The differences between neutrino and antineutrino cross sections, emerging from interference terms, are also discussed