Semileptonic $B_c\to {\eta }_c,J/\psi$ transitions

Abstract

Using a systematic, symmetry-preserving continuum approach to the Standard Model strong-interaction bound-state problem, we deliver parameter-free predictions for all semileptonic $B_c\to {\eta }_c,J/\psi$ transition form factors on the complete domains of empirically accessible momentum transfers. Working with branching fractions calculated therefrom, the following values of the ratios for $\tau$ over $\mu$ final states are obtained: $R_{{\eta }_c}=0.313(22)$ and $R_{J/\psi }=0.242(47)$. Combined with other recent results, our analysis confirms a $2\sigma$ discrepancy between the Standard Model prediction for $R_{J/\psi }$ and the single available experimental result.

arXiv comment8 pages, 4 figures, 5 tables

References in corpus (60)

• Measurement of an Excess of B -> D(*) Tau Nu Decays and Implications for Charged Higgs Bosons
• Measurement of the branching ratio of $\bar{B}\to D^{(\ast )}{\tau }^{-}{\bar{\nu }}_{\tau }$ relative to $\bar{B}\to D^{(\ast )}{\ell }^{-}{\bar{\nu }}_{\ell }$ decays with hadronic tagging at Belle
• Measurement of the ratio of branching fractions $\mathcal{B}({\overline{B}}^0\to D^{\ast +}{\tau }^{-}{\overline{\nu }}_{\tau })/\mathcal{B}({\overline{B}}^0\to D^{\ast +}{\mu }^{-}{\overline{\nu }}_{\mu })$
• pi- and K-meson Bethe-Salpeter Amplitudes
• Semileptonic Meson Decays in the Quark Model: An Update
• Measurement of the $\tau$ lepton polarization and $R(D^{\ast })$ in the decay $\bar{B}\to D^{\ast }{\tau }^{-}{\bar{\nu }}_{\tau }$
• Baryons as relativistic three-quark bound states
• 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
• Goldstone Theorem and Diquark Confinement Beyond Rainbow-Ladder Approximation
• Measurement of the ratio of the $B^0\to D^{\ast -}{\tau }^{+}{\nu }_{\tau }$ and $B^0\to D^{\ast -}{\mu }^{+}{\nu }_{\mu }$ branching fractions using three-prong $\tau$-lepton decays
• QCD at finite temperature and chemical potential from Dyson-Schwinger equations
• Measurement of the ratio of branching fractions $\mathcal{B}(B_c^{+}\to J/\psi {\tau }^{+}{\nu }_{\tau })$/$\mathcal{B}(B_c^{+}\to J/\psi {\mu }^{+}{\nu }_{\mu })$
• Exclusive semileptonic and nonleptonic decays of the Bc meson
• Dynamical Chiral Symmetry Breaking, Goldstone's Theorem and the Consistency of the Schwinger--Dyson and Bethe--Salpeter Equations
• Observation of B_c Mesons in p-bar p Collisions at sqrt{s} = 1.8 TeV
• Interaction model for the gap equation
• Bridging a gap between continuum-QCD and ab initio predictions of hadron observables
• Update: Precision D_s decay constant from full lattice QCD using very fine lattices
• Pion electromagnetic form factor at spacelike momenta
• Weak decays of the B_c meson to charmonium and D mesons in the relativistic quark model
• Using Heavy Quark Spin Symmetry in Semileptonic $B_c$ Decays
• Heavy meson masses and decay constants from relativistic heavy quarks in full lattice QCD
• The pion: an enigma within the Standard Model
• B-meson decay constants: a more complete picture from full lattice QCD
• Commentary on rainbow-ladder truncation for excited states and exotics
• Precise predictions of charmed-bottom hadrons from lattice QCD
• Spectral functions of confined particles
• The semileptonic decays of the B_c meson
• Spectrum of light- and heavy-baryons
• Symmetry, symmetry breaking, and pion parton distributions
• Prospects for the Bc Studies at LHCb
• Effective charge from lattice QCD
• Locating the Gribov horizon
• Implications of new physics in the decays $B_c\to (J/\psi ,{\eta }_c)\tau \nu$
• Empirical Consequences of Emergent Mass
• $R(J/\psi )$ and $B_c^{-}\to J/\psi {\ell }^{-}{\bar{\nu }}_{\ell }$ Lepton Flavor Universality Violating Observables from Lattice QCD
• Challenges in Semileptonic B Decays
• Chiral susceptibility and the scalar Ward identity
• ${\gamma }^{\ast }\gamma \to \eta ,{\eta }^{\prime }$ transition form factors
• Impressions of the Continuum Bound State Problem in QCD
• The decays $B_c\to J/\psi +\bar{\ell }{\nu }_{\ell }$ and $B_c\to J/\psi +\pi (K)$ in covariant confined quark model
• Elastic electromagnetic form factors of vector mesons
• Poincaré-covariant analysis of heavy-quark baryons
• $B_c\to J/\psi$ Form Factors for the full $q^2$ range from Lattice QCD
• Nucleon-to-Roper electromagnetic transition form factors at large-$Q^2$
• Scale-setting, flavour dependence and chiral symmetry restoration
• Spectrum of scalar and pseudoscalar glueballs from functional methods
• The analytic properties of the quark propagator from an effective infrared interaction model
• Nucleon elastic form factors at accessible large spacelike momenta
• Proton tensor charges from a Poincaré-covariant Faddeev equation
• Pseudoscalar glueball mass: a window on three-gluon interactions
• Lepton flavor universality violation in semileptonic tree level weak transitions
• Semileptonic decays $B_c\to ({\eta }_c,J/\psi )l{\bar{\nu }}_l$ in the "PQCD + Lattice" approach
• Model independent investigation of the $R_{J/\psi ,{\eta }_c}$ and ratios of decay widths of semileptonic $B_c$ decays into a P-wave charmonium
• Precision Model-Independent Bounds from Global Analysis of $b\to c\ell \nu$ Form Factors
• Semileptonic decays $B/B_s\to (D^{(\ast )},D_s^{(\ast )})l{\nu }_l$ in the PQCD approach with the lattice QCD input
• K_{l3} transition form factors
• Model-Independent Determination of $B_c^{+}\to {\eta }_c{\ell }^{+}\nu$ Form Factors
• Semileptonic decays of $D_{(s)}$ mesons
• Relativistic calculations of $R(D^{(\ast )})$, $R(D_s^{(\ast )})$, $R({\eta }_c)$ and $R(J/\psi )$

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• $B_c^{-}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){\tau }^{-}(\to {\pi }^{-}{\nu }_{\tau },{\rho }^{-}{\nu }_{\tau },{\ell }^{-}{\bar{\nu }}_{\ell }{\nu }_{\tau }){\bar{\nu }}_{\tau }$ decays with visible final-state kinematics