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arXiv · 1905.08209

The $V_{cb}$ puzzle: an update

Paolo Gambino·Martin Jung·Stefan Schacht
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Abstract

We discuss the impact of the recent untagged analysis of ${B}^0\rightarrow D^{*}l\bar{\nu}_l$ decays by the Belle Collaboration on the extraction of the CKM element $|V_{cb}|$ and provide updated SM predictions for the $b\to c\tau\nu$ observables $R(D^*)$, $P_\tau$, and $F_L^{D^*}$. The value of $|V_{cb}|$ that we find is about $2\sigma$ from the one from inclusive semileptonic $B$ decays, and is very sensitive to the slope of the form factor at zero recoil which should soon become available from lattice calculations.

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Paolo Gambino, Martin Jung, Stefan Schacht. 2019-05-20. The $V_{cb}$ puzzle: an update. https://doi.org/10.1016/j.physletb.2019.06.039

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