Speaker
Description
Superallowed nuclear beta decays offer one of the most precise ways of extracting the CKM matrix |V_ud|, which is an important parameter in the Standard Model. QED radiative corrections play an important role in the precision computation of nuclear beta decays, which can be expressed in a series of Z \alpha and \alpha. Given the current experimental uncertainty, the order Z \alpha^2 correction should be taken into account. In this talk, I show how the virtual contribution to the Z \alpha^2 correction can be computed using factorization in the limit of small electron mass. I demonstrate the formalism by reproducing Sirlin's g function at one loop order, and discuss the inclusion of real photons and finite electron mass for the Z \alpha^2 correction.
