Combined analysis of semileptonic $B$ decays to $D$ and $D^*$: $R(D^{(*)})$, $|V_{cb}|$, and new physics
By F. Bernlochner, Z. Ligeti, D. Robinson. 2017
300 citations recorded by the source corpus.
The measured $\bar{B}\to D^{(*)} l \bar\nu$ decay rates for light leptons ($l=e,\mu$) constrain all $\bar{B}\to D^{(*)}$ semileptonic form factors, by including both the leading and ${\cal O}(\Lambda_{\text{QCD}}/m_{c,b})$ subleading Isgur-Wise functions in the heavy quark effective theory. We perform a novel combined fit to the $\bar{B}\to D^{(*)} l \bar\nu$ decay distributions to predict the $\bar{B} \to D^{(*)} \tau\bar\nu$ rates and determine the CKM matrix element $|V_{cb}|$. Most theoretical and experimental papers have neglected uncertainties in the predictions for form factor ratios at order $\Lambda_{\text{QCD}}/m_{c,b}$, which we include. We also calculate ${\cal O}(\Lambda_{\text{QCD}}/m_{c,b})$ and ${\cal O}(\alpha_s)$ contributions to semileptonic $\bar{B}\to D^{(*)} \ell \bar\nu$ decays for all possible $b \to c$ currents. This result has not been available for the tensor current form factors, and for two of those, which are ${\cal O}(\Lambda_{\text{QCD}}/m_{c,b})$, the corrections are of the same order as approximations used in the literature. These results allow us to determine with improved precision how new physics may affect the $\bar{B}\to D^{(*)} \tau\bar\nu$ rates. Our predictions can be systematically improved with more data; they need not rely on lattice QCD results, although these can be incorporated.
Subfields: Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/6301ddf388c3051fc7cca18994be8d542e38b804
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In Nuclear and High Energy Physics
- J. Camalich
- Marco Nardecchia
- D. London
- Vladimir Vava Gligorov
- Jure Zupan
- Ediotors A. Cerri
- S. Malvezzi
- Luca Di Luzio
Citations in the corpus
- Opportunities in Flavour Physics at the HL-LHC and HE-LHC (2018, background): “, expanding to linear order in ↵s/⇡ and 1/mc,b, there is sufficient differential information in the B ! D(⇤)l⌫ decays to fit to the four Isgur-Wise functions that arise at this order [982, 989].”
- What is the scale of new physics behind the B-flavour anomalies? (2017, background): “A recent EFT fit of RD(∗) can be found for instance in [16].”
- Combined explanations of the b→sμ+μ− and b→cτ−ν¯ anomalies: A general model analysis (2018, methodology): “Following the measurements of RD(∗) , updated studies of the SM predictions were performed [23, 24].”