The lifetime of the $B_c^{-}$ meson and the anomalies in $B\to D^{(\ast )}\tau \nu$

Abstract

We investigate a new constraint on new-physics interpretations of the anomalies observed in $B\to D^{(\ast )}\tau \nu$ decays making use of the lifetime of the $B_c^{-}$ meson. A constraint is obtained by demanding that the rate for $B_c^{-}\to {\tau }^{-}\bar{\nu }$ does not exceed the fraction of the total width that is allowed by the calculation of the lifetime in the standard model. This leads to a very strong bound on new-physics scenarios involving scalar operators since they lift the slight, but not negligible, chiral suppression of the $B_c^{-}\to {\tau }^{-}\bar{\nu }$ amplitude in the standard model. The new constraint renders a scalar interpretation of the enhancement measured in $R_{D^{\ast }}$ implausible, including explanations implementing extra Higgs doublets or certain classes of leptoquarks. We also discuss the complementarity of $R_{D^{(\ast )}}$ and a measurement of the longitudinal polarization of the $\tau$ in the $B\to D^{\ast }\tau \nu$ decay in light of our findings.

6 pages, 2 figs

References in corpus (18)

• Test of lepton universality using $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• On the B to D* tau nu Sensitivity to New Physics
• Measurement of the branching ratio of ${\bar{B}}^0\to D^{\ast +}{\tau }^{-}{\bar{\nu }}_{\tau }$ relative to ${\bar{B}}^0\to D^{\ast +}{\ell }^{-}{\bar{\nu }}_{\ell }$ decays with a semileptonic tagging method
• Confronting lepton flavor universality violation in B decays with high-$p_T$ tau lepton searches at LHC
• Simultaneous Explanation of the $R_K$ and $R(D^{(\ast )})$ Puzzles
• New physics in the weak interaction of $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$
• Leptoquark model to explain the $B$-physics anomalies, $R_K$ and $R_D$
• B-decay Anomalies in a Composite Leptoquark Model
• Simultaneous Explanation of the $R_K$ and $R_{D^{(\ast )}}$ Puzzles: a Model Analysis
• B-meson decay constants: a more complete picture from full lattice QCD
• Charged-Higgs effects in a new B -> D tau nu differential decay distribution
• Analyzing new physics in the decays ${\bar{B}}^0\to D^{(\ast )}{\tau }^{-}{\bar{\nu }}_{\tau }$ with form factors obtained from the covariant quark model
• New Physics in the Visible Final States of $B\to D^{(\ast )}\tau \nu$
• Probing New Physics with $q^2$ distributions in $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$
• Charged Higgs on $B^{-}\to \tau {\bar{\nu }}_{\tau }$ and $\bar{B}\to P(V)\ell {\bar{\nu }}_{\ell }$
• Measurement of the lifetime of the $B_c^{+}$ meson using the $B_c^{+}\to J/\psi {\pi }^{+}$ decay mode
• CP violation in $B\to D\tau {\nu }_{\tau }$ using multi-pion tau decays
• Hadron Spectroscopy, exotics and $B_c^{+}$ physics at LHCb

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