Single spin asymmetries in γ∗γ→πππ at large Q2

The γ∗γ→πππ reaction is analysed in QCD at large photon virtuality Q and small hadronic mass W. Its amplitude factorizes in a 3π generalized distribution amplitude and a hard subprocess γ∗γ→qq̄ or γ∗γ→gg. The interference of this process with a Brehmsstrahlung process in ee or eγ collisions gives rise to interesting single spin asymmetries, particularly when W is near the ω mass.