  Resonant productions of the first generation scalar and vector diquarks at
high energy hadron-hadron (pp), lepton-hadron (ep) and lepton-lepton (e+e-)
colliders are investigated. Taking into account the hadronic component of the
photon, diquarks can be produced resonantly in the lepton-hadron and
lepton-lepton collisions. Production rates, decay widths and signatures of
diquarks are discussed using the general, SU(3)_{C} x SU(2)_{W} x U(1)_{Y}
invariant, effective Lagrangian. The corresponding dijet backgrounds are
examined in the interested invariant mass regions. The attainable mass limits
and couplings are obtained for the diquarks that can be produced in hadron
collisions and in resolved photon processes. It is shown that hadron collider
with center of mass energy sqrt(s)=14 TeV will be able to discover scalar and
vector diquarks with masses up to m_{DQ}=9 TeV for quark-diquark-quark coupling
alpha_{DQ}=0.1. Relatively, lighter diquarks can be probed at ep and e+e-
collisions in more clear environment.
