Parity Violation in Polarized-Gamma Proton Compton Scattering

Polarized beam gamma p Compton scattering provides a theoretically clean way to extract the isovector parity violating pion-nucleon coupling constant $h_{\pi NN}^{(1)}$. This channel is more tractable experimentally than the recently proposed extraction of $h_{\pi NN}^{(1)}$ from the Bedaque-Savage process --- polarized target gamma p compton scattering. The leading parity violating effect is calculated using Heavy Baryon Chiral Perturbation Theory. The size of the asymmetry is estimated to be ~ 4 10^{-8} for 120 MeV photon energy.