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Lattice HQET with exponentially improved statistical precision

M. Della Morte·S. Durr·J. Heitger·H. Molke·J. Rolf·A. Shindler·R. Sommer
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Abstract

We introduce an alternative discretization for static quarks on the lattice retaining the O(a) improvement properties of the Eichten-Hill action. In this formulation, statistical fluctuations are reduced by a factor which grows exponentially with Euclidean time, x_0. For the first time, B-meson correlation functions are computed with good statistical precision in the static approximation for x_0>1 fm. At lattice spacings a \approx 0.1 fm, a \approx 0.08 fm and a \approx 0.07 fm the B_s-meson decay constant is determined in static and quenched approximations. A correction due to the finite mass of the b-quark is estimated by combining these static results with a recent determination of F_Ds.

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M. Della Morte, S. Durr, J. Heitger, H. Molke, J. Rolf, A. Shindler, R. Sommer. 2005-02-23. Lattice HQET with exponentially improved statistical precision. https://doi.org/10.1016/j.physletb.2005.03.017

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