  We investigate the possibility to acquire information on the generalized
parton distribution E and, through a model for E, also on the u-quark total
angular momentum J_u by studying deeply virtual Compton scattering and hard
exclusive rho0 electroproduction on a transversely polarized hydrogen target at
HERMES. It is found that a change in J_u from zero to 0.4 corresponds to a
4\sigma (2\sigma) difference in the calculated transverse target-spin asymmetry
in deeply virtual Compton scattering (rho0 electroproduction), where \sigma is
the total experimental uncertainty.
