Origins of the method to determine the CKM angle ${\hat{I}}^3$ using $B^{\pm }\to D{K}^{\pm }$, $D\to K_{\mathrm{S}}^0\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ decays

Abstract

The angle ${\hat{I}}^3$ of the Cabibbo--Kobayashi--Maskawa unitarity triangle is a benchmark parameter of the Standard Model of particle physics. A method to determine ${\hat{I}}^3$ from $B^{\pm }\to D{K}^{\pm }$ with subsequent $D\to K_{\mathrm{S}}^0\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ or similar multibody decays has been proven to provide good sensitivity. We review the first discussions on the use of this technique, and its impact subsequently. We propose that this approach should be referred to as the BPGGSZ method.