LHCb Observation of photon polarization in the $b\rightarrow s\gamma$ transition

The Standard Model (SM) predicts that the photon emitted in $b\rightarrow s\gamma$ transitions is predominantly left-handed. While the measured inclusive $b\rightarrow s\gamma$ rate agrees with the SM calculations, no direct evidence exists for a nonzero photon polarization $\lambda_\gamma$ in this type of decays. Several extensions of the SM, compatible with all current measurements, predict that the photon acquires a significant right-handed component.