### Conveners

#### Epsilon’/Epsilon

- Elizabeth Worcester

An overview of the kaon physics program of the RBC and UKQCD collaborations will be presented with a focus on the lattice calculation of K->pi-pi decay and the direct CP violation parameter epsilon'. We will describe substantial improvements to our earlier 2015 K->pi-pi calculation, including the use of three independent pi-pi interpolating operators and the results we obtain for I=0 pi-pi...

We present an updated analysis of isospin-violating contributions to eps'/eps in the framework of chiral perturbation theory, taking advantage of the different improvements in the determination of quark masses and nonperturbative parameters. The role of the different pieces entering into the analysis is carefully assessed.

We review the current status of epsilon'/epsilon within the Standard Model, discussing in detail the different ingredients that enter into the calculation of this observable. Both short-distance and long-distance contributions need to be taken into account, within a properly-defined theoretical framework. An update of the Standard Model prediction is presented and the prospects for future...