Kaon Decay into Three Photons Revisited
Abstract
We evaluate the rare radiative kaon decays KL,S -> 3 gamma. Applying the requirements of gauge invariance and Bose symmetry, we derive a general form of the decay amplitude, including both parity-conserving and parity-violating contributions. We employ a chiral-Lagrangian approach combined with dimensional analysis arguments to estimate the branching ratios of these decays in the standard model, obtaining values as large as B(KL -> 3 gamma) ~ 1 x 10-14 and B(KS -> 3 gamma) ~ 2 x 10-17, which exceed those found previously by a few orders of magnitude. Measurements on the branching ratios which are significantly larger than these numbers would likely hint at the presence of new physics beyond the standard model.
0