An exploratory calculation of $K_{\mathrm{L}}\to \hat{I}{¼}^{+}\hat{I}{¼}^{-}$ decay from Lattice QCD at physical pion mass

Peter Boyle, En-Hung Chao, Norman Christ +3

We compute the complex, long-distance two-photon-exchange amplitude which contributes to the rare $K_{\mathrm{L}}\to \hat{I}{¼}^{+}\hat{I}{¼}^{-}$ decay from lattice QCD. We use a $24^3\times 64$ ph…