g g , g p physics at e+e-, ep colliders

• Typical diagrams for gg and gp collisions:

• Main interest of g-induced collisions at LEP & HERA:

  • Precision QCD w/ low bckgd & simpler initial state than hadronic colls.
  • Measurements: s(tot.had), Ggg of 0-+2++, VV production, g structure function,
  • hard photoproduction (Quarkonia, jets, heavy-Q), ...
  • Physics topics: Regge theory, low-energy q spectrosc., BFKL dynamics,
  • hard scatt. factorization, G(x,Q2) distribution, diffractive interactions, ...