Gamma Rays Create Matter Just by Plowing into Laser Light
FEB 01, 1998
Quantum electrodynamics predicts that photons scattering off nothing but light should create electron‐positron pairs. But only now has this inelastic light‐light scattering been seen in the laboratory.
DOI: 10.1063/1.882208
When a beam of 50‐GeV electrons collides head on with a terawatt laser pulse focused down to a few microns, extraordinary things can happen: Almost every electron plowing through the very dense laser field at the focus kicks a low‐energy photon up to multi‐GeV gamma‐ray energy, and lots of these “Compton‐backscattered” gammas then create electron‐positron pairs when they subsequently collide with laser photons coming toward them.
© 1998. American Institute of Physics
