Exclusive production of rho(0) and J/psi mesons in e(+)p collisions has bee
n studied with the ZEUS detector in the kinematic range 0.25 < Q(2) < 50 Ge
V2, 20 < W < 167 GeV for the rho(0) data and 2 < Q(2) < 40 GeV2, 50 < IS' <
150 GeV for the J/psi data. Cross sections for exclusive rho(0) and J/psi,
production have been measured as a function of Q2, W and t. The spin-densi
ty matrix elements r(00)(04), r(1-1)(1) and Rer(10)(5) have been determined
for exclusive rho(0) production as well as r(00)(04) and r(1-1)(04) for ex
clusive J/psi production. The results are discussed in the context of theor
etical models invoking soft and hard phenomena.