Exclusive Electroproduction of $ρ^0$ and $J/ψ$ Mesons at HERA

Paper

Abstract

Exclusive production of

and

mesons in e^+ p collisions has been studied with the ZEUS detector in the kinematic range

for the

data and

for the

data. Cross sections for exclusive

and

production have been measured as a function of

and

. The spin-density matrix elements

and

have been determined for exclusive

production as well as

and

for exclusive

production. The results are discussed in the context of theoretical models invoking soft and hard phenomena.