Lattice QCD Calculation of Electroweak Box Contributions to Superallowed Nuclear and Neutron Beta Decays

Peng-Xiang Ma, Xu Feng, Mikhail Gorchtein +5

We present the first lattice QCD calculation of the universal axial ${\hat{I}}^{3}W$-box contribution ${\square }_{{\hat{I}}^{3}W}^{VA}$ to both superallowed nuclear and neutron beta decays. This contribut…