A High Statistics Lattice Calculation of $f_B^{static}$ at $\beta =6.2$ Using the Clover Action

Abstract

We present a calculation of $f_B$ in the static limit, obtained by numerical simulation of quenched QCD, at $\beta =6.2$ on a $18^3\times 64$ lattice, using the SW-Clover quark action. The decay constant has been extracted by studying heavy(static)-light correlation functions of different smeared operators, on a sample of 220 gauge field configurations. We have obtained $f_B^{static}=(290\pm 15\pm 45)$ MeV, where the first error comes from the uncertainty in the determination of the matrix element and the second comes from the uncertainty in the lattice spacing. We also obtain $M_{B_s}-M_{B_d}=(70\pm 10)$ MeV and $f_{B_s}^{stat}/f_{B_d}^{stat}=1.11(3)$. A comparison of our results with other calculations of the same quantity is made.

Comments: 12 pages, LaTex, 3 figs. (figures not included; available upon request from lubicz@roma1.infn.it) ROME prep. 94/981, 18 February 1994