The 34th International Symposium on Lattice Field Theory (Lattice 2016)

Jul 24 – 30, 2016
Highfield Campus, University of Southampton
Europe/London timezone

Leptonic decay-constant ratio $f_K/f_\pi$ from clover-improved $N_f=2+1$ QCD

Jul 28, 2016, 2:40 PM
20m
Building 67 Room 1003 (Highfield Campus, University of Southampton)

Building 67 Room 1003

Highfield Campus, University of Southampton

Highfield Campus, Southampton SO17 1BJ, UK
Talk Weak Decays and Matrix Elements

Speaker

Dr Enno E. Scholz (University of Regensburg)

Description

The leptonic decay-constant ratio $f_K/f_\pi$ is calculated from lattice-QCD simulations using $N_f=2+1$ dynamical fermion flavors in the clover-improved formulation and 2-HEX smearing. The simulations were performed at a range of mass-degenerate light quarks including the physical point and at various lattice couplings and volumes, allowing to quantify all relevant sources of systematic uncertainties for our final number of the decay-constant ratio. Utilizing input from ChPT, we also quote the charged decay-constant ratio $f_{K^\pm}/f_{\pi^\pm}$. With further input from super-allowed nuclear $\beta$-decays, eventually we obtain an estimate for the CKM-matrix element $V_{\rm us}$.

Primary author

Dr Enno E. Scholz (University of Regensburg)

Co-author

Dr Stephan Durr (University of Wuppertal)

 Slides