STUDIES OF NONLINEAR QED IN HIGH-ENERGY ELECTRON-LASER COLLISIONS

We discuss results obtained at the Stanford Linear Accelerator Center in the interaction of 46.6 GeV electrons crossing through the focus of a terawatt laser at lambda = 527 nm. Under those circumstances the fi eld seen in the electron rest frame approaches the critical field of Q ED. Multiphoton Compton scattering with the absorption of as many as 4 photons from the laser field as well as e(+)e(-)pair production in th e collision of a high energy gamma with several laser photons were obs erved. This is the first evidence for strong QED interactions and the data agree with the theoretical predictions. Furthermore this is the f irst observation of inelastic light-by-light scattering involving only real photons.