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 Delta(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 Delta excitation holds due to large cancellations among the background contributions. We consider two sets of vector and axial-vector N-Delta transition form factors, evidencing the strong sensitivity of the results to the axial coupling C-5(A)(0). The differences between neutrino and antineutrino cross sections, emerging from interference terms, are also discussed.