$B\to D^\ast\ell\nu$ at non-zero recoil

A. Vaquero; C. DeTar; A. X. El-Khadra; A. S. Kronfeld; J. Laiho; R. S. Van de Water

$B\to D^\ast\ell\nu$ at non-zero recoil

High Energy Physics - Lattice 2019-06-11 v2 High Energy Physics - Experiment

Authors: A. Vaquero , C. DeTar , A. X. El-Khadra , A. S. Kronfeld , J. Laiho , R. S. Van de Water

Abstract

The current status of the lattice-QCD calculations of the form factors of the $B\to D^\ast\ell\nu$ semileptonic decay is reviewed. Particular emphasis is given to the most mature calculation at non-zero recoil coming from the Fermilab Lattice and MILC collaborations. Blinded, preliminary results for the form factors are shown, including a preliminary, but detailed error budget. The lattice results seem to favor a large slope at small recoil, in contrast to the latest untagged results coming from the Belle collaboration. A comprehensive comparison between the latest BGL $z$ expansions of Belle, Babar, the lattice and a joint BGL fit including lattice and Belle data is presented, and a roadmap to improve the current calculation is discussed. The current implications for $V_{cb}$ and $R(D^\ast)$ are discussed.

Keywords

lattice qcd form factors b to d* semileptonic decay non-zero recoil bgl z expansion v_cb r(d*)

Cite

@article{arxiv.1906.01019,
  title  = {$B\to D^\ast\ell\nu$ at non-zero recoil},
  author = {A. Vaquero and C. DeTar and A. X. El-Khadra and A. S. Kronfeld and J. Laiho and R. S. Van de Water},
  journal= {arXiv preprint arXiv:1906.01019},
  year   = {2019}
}

Comments

8 pages, 12 figures. Proceedings of the 2019 Conference on Flavor Physics and CP Violation (FPCP2019). v2 fixes the contour plots of the coefficients of the BGL expansion for BaBar results (b1/b0 and c1/c0)

$B\to D^\ast\ell\nu$ at non-zero recoil

Abstract

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