  Final state quark-antiquark interactions may give origin to non zero values
of the off-diagonal element rho_{1,-1} of the helicity density matrix of vector
mesons produced in e+e- annihilations, as confirmed by recent OPAL data on phi
and D^*'s. Predictions are given for rho_{1,-1} of several mesons produced at
large z and small p_T, i.e. collinear with the parent jet; the values obtained
for phi and D^* are in agreement with data.
