We report on the first measurement of cross sections for exclusive deeply
virtual pion electroproduction off the proton, ep→e′nπ+,
above the resonance region at backward pion center-of-mass angles. The
φπ∗-dependent cross sections were measured, from which we
extracted three combinations of structure functions of the proton. Our results
are compatible with calculations based on nucleon-to-pion transition
distribution amplitudes (TDAs) and shed new light on nucleon structure.Comment: 7 pages, 6figure