A precise determination of the decay constant of the Ds-meson in quenched QCD

Abstract

We present a lattice determination of the leptonic decay constant F_Ds of the Ds-meson using its mass and F_K as experimental input. Setting the scale with F_K=160 MeV, our final result is F_Ds = 252(9) MeV. The error contains all uncertainties apart from the quenched approximation. Setting the scale with the nucleon mass instead leads to an increase of 3(1) MeV of the leptonic decay constant which might indicate a small quenching error.

Comments: 8 pages, 1 figure, references added, mistake in the computation of the quenched scale ambiguity of the decay constant corrected