Model-Independent Bounds on $R(J/\psi )$

Abstract

We present a model-independent bound on $R(J/\psi )\equiv \mathcal{B}\mathcal{R}(B_c^{+}\to J/\psi {\tau }^{+}{\nu }_{\tau })/\mathcal{B}\mathcal{R}(B_c^{+}\to J/\psi {\mu }^{+}{\nu }_{\mu })$. This bound is constructed by constraining the form factors through a combination of dispersive relations, heavy-quark relations at zero-recoil, and the limited existing determinations from lattice QCD. The resulting 95\% confidence-level bound, $0.20\le R(J/\psi )\le 0.39$, agrees with the recent LHCb result at $1.3\sigma$, and rules out some previously suggested model form factors.

19 pages, 4 figures, JHEP format, revised to match published version

References in corpus (7)

• Exclusive semileptonic and nonleptonic decays of the Bc meson
• $R(D^{\ast })$, $|V_{cb}|$, and the Heavy Quark Symmetry relations between form factors
• Extraction of $|V_{cb}|$ from $B\to D^{(\ast )}\ell {\nu }_{\ell }$ and the Standard Model predictions of $R(D^{(\ast )})$
• Study of exclusive semileptonic and nonleptonic decays of $B_c^{-}$ in a nonrelativistic quark model
• New Physics effect on $B_c\to J/\psi \tau \bar{\nu }$ in relation to the $R_{D^{(\ast )}}$ anomaly
• Lattice QCD calculation of the $B_{(s)}\to D_{(s)}^{\ast }\ell \nu$ form factors at zero recoil and implications for $|V_{cb}|$
• The decays $B_c\to J/\psi +\bar{\ell }{\nu }_{\ell }$ and $B_c\to J/\psi +\pi (K)$ in covariant confined quark model

Cited by in corpus (31)

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• Footprints of New Physics in $b\to c\tau \nu$ Transitions
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• Revisiting the new-physics interpretation of the $b\to c\tau \nu$ data
• Unified Framework for $B$-Anomalies, Muon $g-2$, and Neutrino Masses
• On lepton flavour universality in semileptonic $B_c\to {\eta }_c,J/\psi$ decays
• Unified explanation of flavor anomalies, radiative neutrino mass and ANITA anomalous events in a vector leptoquark model
• $B_c\to J/\psi$ Form Factors for the full $q^2$ range from Lattice QCD
• $b\to c\tau \nu$ Transitions in the Standard Model Effective Field Theory
• Charged current $b\to c\tau {\bar{\nu }}_{\tau }$ anomalies in a general $W^{\prime }$ boson scenario
• Impact of ${\Lambda }_b\to {\Lambda }_c\tau \nu$ measurement on New Physics in $b\to cl\nu$ transitions
• 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
• Maximizing the Impact of New Physics in $b\to c\tau \nu$ Anomalies
• Review of Semileptonic $B$ Anomalies
• $B_s\to D_s^{\ast }$ Form Factors for the full $q^2$ range from Lattice QCD
• Precision Model-Independent Bounds from Global Analysis of $b\to c\ell \nu$ Form Factors
• Model-Independent Determination of $B_c^{+}\to {\eta }_c{\ell }^{+}\nu$ Form Factors
• $R_{D^{(\ast )}}$ in custodial warped space
• Model-Independent Prediction of $R({\eta }_c)$
• Implication of $R_{D^{(\ast )}}$ anomalies on semileptonic decays of ${\Sigma }_b$ and ${\Omega }_b$ baryons
• Implication of $b\to c\tau \nu$ flavor anomalies on $B_s\to D_s^{\ast }\tau \nu$ decay observables
• New physics footprints in the angular distribution of $B_s\to D_s^{\ast }(\to D_s\gamma ,D_s\pi )\tau \nu$ decays
• $D^{\ast }$ Polarization as an Additional Constraint on New Physics in the $b\to c\tau {\bar{\nu }}_{\tau }$ Transition
• $|V_{ub}|$ determination and testing of lepton flavour universality in semileptonic $B_c\to D^{(\ast )}$ decays
• New physics in the angular distribution of $B_c^{-}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){\tau }^{-}(\to {\pi }^{-}{\nu }_{\tau }){\bar{\nu }}_{\tau }$ decay
• Probing New Physics in light of recent developments in $b\to c\ell \nu$ transitions
• Analyzing the semileptonic and nonleptonic $B_c\to J/\psi ,{\eta }_c$ decays
• Relations between $b\to c\tau \nu$ Decay Modes in Scalar Models
• Nonleptonic $B_c$ decay rates from model independent relations