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arXiv · 1711.01158

HQET form factors for $B_s\to K\ell\nu$ decays beyond leading order

Debasish Banerjee·Mateusz Koren·Hubert Simma·Rainer Sommer
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Abstract

We compute semi-leptonic $B_s$ decay form factors using Heavy Quark Effective Theory on the lattice. To obtain good control of the $1/m_b$ expansion, one has to take into account not only the leading static order but also the terms arising at $O(1/m_b)$: kinetic, spin and current insertions. We show results for these terms calculated through the ratio method, using our prior results for the static order. After combining them with non-perturbative HQET parameters they can be continuum-extrapolated to give the QCD form factor correct up to $O(1/m_b^2)$ corrections and without $O(\alpha_s(m_b)^n)$ corrections.

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Debasish Banerjee, Mateusz Koren, Hubert Simma, Rainer Sommer. 2017-11-03. HQET form factors for $B_s\to K\ell\nu$ decays beyond leading order. https://doi.org/10.1051/epjconf%2F201817513025

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