A new theory framework for the electroweak radiative corrections in K l3 decays

Abstract

Abstract We propose a new theory framework to study the electroweak radiative corrections in K l3 decays by combining the classic current algebra approach with the modern effective field theory. Under this framework, the most important O $$ \mathcal{O} $$ (G F α) radiative corrections are described by a single tensor T μν involving the time-ordered product between the charged weak current and the electromagnetic current, and all remaining pieces are calculable order-by-order in Chiral Perturbation Theory. We further point out a special advantage in the K l 3 0 $$ {K}_{l3}^0 $$ channel that it suffers the least impact from the poorly-constrained low-energy constants. This finding may serve as a basis for a more precise extraction of the matrix element V us in the future.

Keywords

• Chiral Lagrangians
• Kaon Physics
• Precision QED