Speaker
Mr
Kyle Shiells
(University of Manitoba)
Description
The CKM matrix of the Standard Model (SM) is a unitary $3\times3$ matrix which holds information on how strongly the various quark flavours couple to each other. Consequently, nature’s adherence to the SM can be tested by the normalization condition of its rows. $|V_{ud}| = 0.97417(21)$ is a dominant term in the first row unitarity condition: $|V_{ud}|^2 + |V_{us}|^2 + |V_{ub}|^2 = 1$, and thus carries more weight than its 2 neighbours. The largest source of its uncertainty comes from a troublesome, model-dependent radiative correction: the $\gamma W$ box. I outline a new way to calculate this Feynman diagram using dispersion relations, which lead to a more realistic value of $V_{ud}$ and its uncertainty estimate.
Author
Mr
Kyle Shiells
(University of Manitoba)
