Speaker
Description
The parameter ᵱᵃ is an important measure of the
imbalance between matter and antimatter in the neutral kaon (ᵃ0 and ᵃ¯0)
system. In particular, ᵱᵃ provides a highly sensitive probe of new physics and
plays a critical role in the global fit of the Cabibbo-Kobayashi-Maskawa matrix. As
one of the first discovered sources of ᵃᵄ violation, it has been extensively
measured in experiment to per-mil precision. The theoretical calculation of ᵱᵃ,
however, has historically been plagued by large perturbative errors arising from
charm-quark corrections. These errors were larger than the expected magnitude of
higher-order electroweak corrections in perturbation theory, rendering these
contributions irrelevant. Recently, it was discovered that a simple
re-parameterization of the effective Hamiltonian drastically reduces perturbative
errors, making these higher-order electroweak calculations worth-while. We
present the next-to-leading-logarithm electroweak contributions to ᵱᵃ.
