TY  - JOUR
AU  - Dürr, Stephan
AU  - Fodor, Zoltán
AU  - Hoelbling, Christian
AU  - Krieg, Stefan
AU  - Lellouch, Laurent
AU  - Lippert, Thomas
AU  - Rae, Thomas
AU  - Schäfer, Andreas
AU  - Scholz, Enno E.
AU  - Szabo, Kalman
AU  - Varnhorst, Lukas
TI  - Leptonic decay-constant ratio $f_K/f_\pi$ from lattice QCD using 2+1 clover-improved fermion flavors with 2-HEX smearing
JO  - Physical review / D
VL  - 95
IS  - 5
SN  - 2470-0010
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2017-02609
SP  - 054513
PY  - 2017
AB  - We present a calculation of the leptonic decay-constant ratio $f_K/f_\pi$ in 2+1 flavor QCD, performed via a series of lattice studies, which allows us to quantify all sources of systematic uncertainty. Our final result is $f_K/f_\pi=1.182(28)$, and with isospin breaking corrections from ChPT the charged decay-constant ratio reads $f_{K^\pm}/f_{\pi^\pm}=1.178(28)$. With $V_\mathrm{ud}$ from super-allowed nuclear beta decays, the CKM matrix element $V_\mathrm{us}=0.2282(54)$ is perfectly compatible with the first-row unitarity constraint of the Standard Model.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000399145800003
DO  - DOI:10.1103/PhysRevD.95.054513
UR  - https://juser.fz-juelich.de/record/828743
ER  -