Ratio F-K/F-pi in QCD
Durr, S; Fodor, Z; Hoelbling, C; Katz, SD; Krieg, S; Kurth, T; Lellouch, L; Lippert, T; Ramos, A; Szabo, KK
WoS ID: 000276194200075
Scopus ID: 77950556904
We determine the ratio F-K/ F-pi in QCD with N-f =2 + 1 flavors of sea quarks, based on a series of lattice calculations with three different lattice spacings, large volumes, and a simulated pion mass reaching down to about 190 MeV. We obtain F-K / F-pi = 1.192(7)(stat)(6)(syst). This result is then used to give an updated value of the Cabibbo-Kobayashi-Maskawa) matrix element vertical bar V-us vertical bar. The unitarity relation for the first row of this matrix is found to be well observed.