The 39th International Symposium on Lattice Field Theory (Lattice 2022)

Lattice calculation of leading isospin breaking effects in $\Gamma(K_{\ell 2})/\Gamma(\pi_{\ell 2})$ with close-to-physical chiral fermions

Aug 10, 2022, 2:00 PM

20m

CP1-HSZ/1.002 (CP1-HSZ) - HS6 (CP1-HSZ)

Oral Presentation Weak Decays and Matrix Elements Weak Decays and Matrix Elements

Speaker

Matteo Di Carlo (University of Edinburgh)

Description

In this talk we present the first RBC-UKQCD lattice calculation of the leading isospin-breaking corrections to the ratio of leptonic decay rates of kaons and pions into muon and neutrino, $\Gamma(K_{\ell 2})/\Gamma(\pi_{\ell 2})$. This computation is performed using domain wall fermions with close-to-physical (light and strange) quark masses. The QED effects are implemented using a perturbative approach and infrared divergences are regulated according to the QED$_\mathrm{L}$ prescription. We describe the strategy to extract the relevant hadronic matrix elements from Euclidean correlation functions and we discuss the important role of finite volume effects in this calculation.

Presentation materials

lattice2022_mdc_v2.pdf