Constraints on Extra Gauge Bosons in e gamma Collisions
  We investigate the sensitivity of e- gamma ---> nu_e nu_mu(bar) mu- to extra charged gauge bosons. The sensitivity is much below that of e-e+ ---> nu nu(bar) gamma. We conclude that e- gamma ---> d u(bar) nu_e and e- gamma ---> f f(bar) e- are also inferior to e+e- collisions in setting bounds on extra charged and neutral gauge bosons and on four fermion contact interactions. 
Stephen Godfrey, Pat Kalyniak, Basim Kamal, Arnd Leike