We discuss the recent data of exclusive $\pi^0$ (and $\pi^+$) electroproduction on the proton obtained by the CLAS collaboration at Jefferson Lab. It is observed that the cross sections, which have been decomposed in $\sigma_T +\epsilon\sigma_L$, $\sigma_{ TT}$ and $\sigma_{ LT}$ structure functions, are dominated by transverse amplitude contributions. The data can be interpreted in the Generalized Parton Distribution formalism provided that one includes helicity-flip transversity GPDs.
Categories: hep-ex hep-ph