Seminarium Fizyki Jądra Atomowego

The superallowed 0⁺ -> 0⁺ Fermi transitions provide the most accurate estimate of the V_ud matrix element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix and, in turn, stringent test of the CKM unitarity. From a nuclear structure perspective the V_ud and CKM unitarity depend critically on a set of theoretically calculated radiative and isospin-breaking corrections. In my talk, I shall discuss isospin mixing in atomic nuclei, a prerequisite for the calculations of isospin-breaking corrections, and present first fully microscopic calculations of the isospin-breaking corrections to the superallowed beta decay based on angular-momentum and isospin projected density functional theory.