SINGLE LEPTOQUARK PRODUCTION AT HADRON COLLIDERS

Leptoquarks can be produced in pairs by gluon-gluon fusion and quark-a ntiquark annihilation at hadron colliders. While HERA is the proper ma chine for single production of (eu) and (ed) type leptoquarks, the fla vor species of (muu), (mud) and (tauu), (taud) type leptoquarks can be produced at hadron colliders very efficiently. Besides exploiting glu on-quark collisions, leptoquarks can also be produced singly by collid ing the quarks in one proton beam with leptons e, mu, tau generated by splitting photons which are radiated off the quarks in the other prot on beam. For Yukawa couplings of the size alpha leptoquark masses up t o about 300 GeV can be generated at the Tevatron while the LHC can pro duce leptoquarks with masses up to about 3 TeV. [Leptoquarks involving heavy quarks can be produced singly at a lower rate, determined by th e heavy flavor flux in the proton beam.]