Towards a non-perturbative matching of HQET and QCD with dynamical light quarks

Abstract

We explain how the strategy of solving renormalization problems in HQET non-perturbatively by a matching to QCD in finite volume can be implemented to include dynamical fermions. As a primary application, some elements of an HQET computation of the mass of the b-quark beyond the leading order with N f = 2 are outlined. In particular, the matching of HQET and QCD requires relativistic QCD simulations in a volume with L ≈ 0.5 fm, which will serve to quantitatively determine the heavy quark mass dependence of heavy-light meson observables in the continuum limit of finite-volume two-flavour lattice QCD. As a preparation for the latter, we report on our determination of the renormalization constants and improvement coefficients relating the renormalized current and subtracted bare quark mass in the relevant weak coupling region. The calculation of these coefficients employs a constant physics condition in the Schrödinger functional scheme, where the box size L is fixed by working at a prescribed value of the renormalized coupling.

Towards precision heavy flavour physics from lattice QCD

“…While the numerical computations in lattice QCD necessarily involve approximations, one of the key features of the lattice approach is that all approximations can be systematically improved. For an overview of the different formulations of heavy quarks on the lattice that have been proposed in the literature and are being used today, and of results from the field of heavy flavour physics, which reflect some of these improvements by the small error bars quoted for many quantities, I refer to the reviews of past Lattice Conferences [3,4,5,6,7] and references therein.…”