Abstract : We discuss two aspects of polarisation in hard exclusive meson production: the leading-twist selection rule for the meson helicity, and the different partial waves of a (pi pi)-pair which may or may not be due to the decay of a rho.
M. Diehl, T. Gousset, B. Pire. Polarisation in deeply virtual meson production. Workshop on Exclusive and Semiexclusive Processes at High Momentum Transfer, May 1999, Newport, United States. World Scientific, pp.184-191, 2000. <in2p3-00195554>