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arXiv · 1909.10691

Precision Model-Independent Bounds from Global Analysis of $b \to c \ell \nu$ Form Factors

Thomas D. Cohen·Henry Lamm·Richard F. Lebed
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Abstract

We present a model-independent global analysis of hadronic form factors for the semileptonic decays $b\rightarrow c\ell\nu$ that exploits lattice-QCD data, dispersion relations, and heavy-quark symmetries. The analysis yields predictions for the relevant form factors, within quantifiable bounds. These form factors are used to compute the semileptonic ratios $R(H_c)$ and various decay-product polarizations. In particular, we find $R(D_s^*)=0.20(3)$ and $R(J/\psi)=0.25(3)$, predictions that can be compared to results of upcoming LHCb measurements. In developing this treatment, we obtain leading-order NRQCD results for the nonzero-recoil relations between the $B_c^+ \rightarrow \{J/\psi , \eta_c \}$ form factors.

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Thomas D. Cohen, Henry Lamm, Richard F. Lebed. 2019-09-24. Precision Model-Independent Bounds from Global Analysis of $b \to c \ell \nu$ Form Factors. https://doi.org/10.1103/physrevd.100.094503

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