Probing generalized parton distributions in πN→ℓ+ℓ−N

We study the exclusive reactions π−p→ℓ+ℓ−n and π+n→ℓ+ℓ−p in view of possible future experiments with high-intensity pion beams. For large invariant mass of the lepton pair ℓ+ℓ− and small squared momentum transfer to the nucleon these are hard-scattering processes providing access to generalized parton distributions. We estimate the cross section for these reactions, explore their connection with the pion form factor, and discuss the role they can play in improving our understanding of the relevant reaction mechanisms.