Master Formula Approach to γγ → ππ processes

  title={Master Formula Approach to γγ → ππ processes},
  author={Sasha Chernyshev and Ismail Zahed},
We analyze the γγ → π 0 π 0 and γγ → π + π − reactions using the master formula approach to chiral symmetry breaking. The pertinent vacuum correlators are estimated at tree level, and the results are compared with one-and two-loop chiral perturbation theory. The Compton scattering amplitude and the pion polarizabilities are also discussed.