Measurement of the $\tau$ lepton polarization and $R(D^{\ast })$ in the decay $\bar{B}\to D^{\ast }{\tau }^{-}{\bar{\nu }}_{\tau }$ with one-prong hadronic $\tau$ decays at Belle

Abstract

With the full data sample of $772\times 10^6$ $B\bar{B}$ pairs recorded by the Belle detector at the KEKB electron-positron collider, the decay $\bar{B}\to D^{\ast }{\tau }^{-}{\bar{\nu }}_{\tau }$ is studied with the hadronic $\tau$ decays ${\tau }^{-}\to {\pi }^{-}{\nu }_{\tau }$ and ${\tau }^{-}\to {\rho }^{-}{\nu }_{\tau }$. The $\tau$ polarization $P_{\tau }(D^{\ast })$ in two-body hadronic $\tau$ decays is measured, as well as the ratio of the branching fractions $R(D^{\ast })=\mathcal{B}(\bar{B}\to D^{\ast }{\tau }^{-}{\bar{\nu }}_{\tau })/\mathcal{B}(\bar{B}\to D^{\ast }{\ell }^{-}{\bar{\nu }}_{\ell })$, where ${\ell }^{-}$ denotes an electron or a muon. Our results, $P_{\tau }(D^{\ast })=-0.38\pm 0.51{(\mathrm{stat})}_{-0.16}^{+0.21}(\mathrm{syst})$ and $R(D^{\ast })=0.270\pm 0.035{(\mathrm{stat})}_{-0.025}^{+0.028}(\mathrm{syst})$, are consistent with the theoretical predictions of the Standard Model. The polarization values of $P_{\tau }(D^{\ast })>+0.5$ are excluded at the 90\% confidence level.

arXiv comment17 pages, 11 figures, submitted to Physical Review D

References in corpus (44)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• Evidence for an excess of B -> D(*) Tau Nu decays
• 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 $\mathcal{B}({\overline{B}}^0\to D^{\ast +}{\tau }^{-}{\overline{\nu }}_{\tau })/\mathcal{B}({\overline{B}}^0\to D^{\ast +}{\mu }^{-}{\overline{\nu }}_{\mu })$
• Semileptonic Meson Decays in the Quark Model: An Update
• Measurement of the $\tau$ lepton polarization and $R(D^{\ast })$ in the decay $\bar{B}\to D^{\ast }{\tau }^{-}{\bar{\nu }}_{\tau }$
• On the B to D* tau nu Sensitivity to New Physics
• Dispersive Bounds on the Shape of B -> D^(*) l nu Form Factors
• 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
• Testing leptoquark models in $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$
• The $B\to D\ell \nu$ form factors at nonzero recoil and $|V_{cb}|$ from $2+1$-flavor lattice QCD
• Flavor models for $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$
• Explaining B->Dτν, B->D*τνand B->τνin a 2HDM of type III
• Precision Corrections to Dispersive Bounds on Form Factors
• $B\to Dl\nu$ Form Factors at Non-Zero Recoil and Extraction of $|V_{cb}|$
• New physics in the weak interaction of $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$
• Sensitivity to charged scalars in $B\to D^{(\ast )}\tau {\nu }_{\tau }$ and $B\to \tau {\nu }_{\tau }$ decays
• Scalar contributions to $b\to c(u)\tau \nu$ transitions
• Electron Identification in Belle
• Semileptonic B decays to excited charmed mesons
• Diagnosing New Physics in $b\to c\tau {\nu }_{\tau }$ decays in the light of the recent BaBar result
• Minimally flavored colored scalar in $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$ and the mass matrices constraints
• Study of Exclusive B->X_u l nu Decays and Extraction of |V_{ub}| using Full Reconstruction Tagging at the Belle Experiment
• Revisiting the one leptoquark solution to the $R(D^{(\ast )})$ anomalies and its phenomenological implications
• Charged Higgs Effects on Exclusive Semi-tauonic $\bbox{B}$ Decays
• On the anomalous enhancement observed in $B\to D^{(\ast )}\tau {\bar{\nu }}_{\tau }$ decays
• Observation of B^0 \to D^{*-} τ^+ ν_τ decay at Belle
• Observation of B+ -> Dbar*0 tau+ nu_tau and Evidence for B+ -> Dbar^0 tau+ nu_tau at Belle
• Tau longitudinal polarization in B -> D tau nu and its role in the search for charged Higgs boson
• Observation of the Semileptonic Decays B --> D* tau nubar and Evidence for B --> D tau nubar
• A closer look at the $R_D$ and $R_{D^{\ast }}$ anomalies
• A Hierarchical NeuroBayes-based Algorithm for Full Reconstruction of B Mesons at B Factories
• The Azimuthal $B\to D^{\ast }{\tau }^{-}\overline{{\nu }_{\tau }}$ Angular Distribution with Tensor Operators
• Probing New Physics with $q^2$ distributions in $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$
• Optimal-observable analysis of possible new physics in $B\to D^{(\ast )}\tau {\nu }_{\tau }$
• Semileptonic $B_{(s)}$ decays to excited charmed mesons with $e,\mu ,\tau$ and searching for new physics with $R(D^{\ast \ast })$
• Improving constraints on tan(beta)/m_H using B \to D tau \bar{nu}
• Tauonic B decays in the Minimal Supersymmetric Standard Model
• Observation of B -> D^{(*)} K^- K^{0(*)} decays
• CP violation in $B\to D\tau {\nu }_{\tau }$ using multi-pion tau decays
• Measurement of Time-Dependent CP-Violating Asymmetries in $B_0\to K_s{K}_s{K}_s$ Decay
• Study of $D^{\ast \ast }$ production and light hadronic states in the ${\bar{B}}^0\to D^{\ast +}\omega {\pi }^{-}$ decay

Cited by in corpus (147)

• Test of lepton universality in beauty-quark decays
• Test of Lepton Flavor Universality by the measurement of the $B^0\to D^{\ast -}{\tau }^{+}{\nu }_{\tau }$ branching fraction using three-prong $\tau$ decays
• Measurement of the ratio of branching fractions $\mathcal{B}(B_c^{+}\to J/\psi {\tau }^{+}{\nu }_{\tau })$/$\mathcal{B}(B_c^{+}\to J/\psi {\mu }^{+}{\nu }_{\mu })$
• Measurement of $\mathcal{R}(D)$ and $\mathcal{R}(D^{\ast })$ with a semileptonic tagging method
• 50 Years of Quantum Chromodynamics
• Maximal Flavour Violation: a Cabibbo mechanism for leptoquarks
• The $V_{cb}$ puzzle: an update
• The Mono-Tau Menace: From $B$ Decays to High-$p_T$ Tails
• Impact of polarization observables and $B_c\to \tau \nu$ on new physics explanations of the $b\to c\tau \nu$ anomaly
• Addendum to "Impact of polarization observables and $B_c\to \tau \nu$ on new physics explanations of the $b\to c\tau \nu$ anomaly"
• Low-energy phenomenology of scalar leptoquarks at one-loop accuracy
• With or without U(2)? Probing non-standard flavor and helicity structures in semileptonic B decays
• $B_s\to D_s\ell \nu$ Form Factors for the full $q^2$ range from Lattice QCD with non-perturbatively normalized currents
• Large long-distance contributions to the electric dipole moments of charged leptons in the standard model
• $B$ Flavour Anomalies: 2021 Theoretical Status Report
• Semileptonic form factors for $B\to D^{\ast }\ell \nu$ at nonzero recoil from 2 + 1-flavor lattice QCD
• A Model of Muon Anomalies
• Observation of the decay ${\Lambda }_b^0\to {\Lambda }_c^{+}{\tau }^{-}{\overline{\nu }}_{\tau }$
• Semitauonic $b$-hadron decays: A lepton flavor universality laboratory
• Measurement of the ratios of branching fractions $\mathcal{R}(D^{\ast })$ and $\mathcal{R}(D^0)$
• $R(J/\psi )$ and $B_c^{-}\to J/\psi {\ell }^{-}{\bar{\nu }}_{\ell }$ Lepton Flavor Universality Violating Observables from Lattice QCD
• Challenges in Semileptonic B Decays
• Quark level and hadronic contributions to the electric dipole moment of charged leptons in the standard model
• Test of lepton flavour universality using $B^0\to D^{\ast -}{\tau }^{+}{\nu }_{\tau }$ decays with hadronic $\tau$ channels
• Search for singly and pair-produced leptoquarks coupling to third-generation fermions in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Addressing the ${\mathbf{R}}_{D^{(\ast )}}$ anomalies with an ${\mathbf{S}}_1$ leptoquark from $\mathbf{SO}(10)$ grand unification
• $|V_{cb}|$ and $R(D^{(\ast )})$ using lattice QCD and unitarity
• B-meson charged current anomalies: the post-Moriond status
• Unveiling Hidden Physics at the LHC
• The role of right-handed neutrinos in $b\to c\tau \bar{\nu }$ anomalies
• Gauging the accidental symmetries of the Standard Model, and implications for the flavour anomalies
• Lattice QCD form factor for $B_s\to D_s^{\ast }l\nu$ at zero recoil with non-perturbative current renormalisation
• Hunting scalar leptoquarks with boosted tops and light leptons
• Flavour alignment in multi-Higgs-doublet models
• Flavor Anomalies in Heavy Quark Decays
• Unitarity Bounds for Semileptonic Decays in Lattice QCD
• Review of searches for vector-like quarks, vector-like leptons, and heavy neutral leptons in proton-proton collisions at $\sqrt{s}$ = 13 TeV at the CMS experiment
• Anomalies in Particle Physics
• $b\to c\tau \nu$ Transitions in the Standard Model Effective Field Theory
• Asymmetry Observables and the Origin of $R_{D^{(\ast )}}$ Anomalies
• 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
• Search for a singly produced third-generation scalar leptoquark decaying to a $\tau$ lepton and a bottom quark in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Constraints for the semileptonic $B\to D^{(\ast )}$ form factors from lattice QCD simulations of two-point correlation functions
• Bottom-Flavored Mono-Tau Tails at the LHC
• Combined explanation of $W$-mass, muon $g-2$, $R_{K^{(\ast )}}$ and $R_{D^{(\ast )}}$ anomalies in a singlet-triplet scalar leptoquark model
• On the significance of new physics in $b\to s{\ell }^{+}{\ell }^{-}$ decays
• Precise limits on the charge-$2/3$ $U_1$ vector leptoquark
• Test of the universality of $\tau$ and $\mu$ lepton couplings in $W$-boson decays from $t\bar{t}$ events with the ATLAS detector
• Correlating Tauonic B Decays to the Neutron EDM via a Scalar Leptoquark
• Lepton flavor universality violation in semileptonic tree level weak transitions
• Inclusive semileptonic ${\Lambda }_b$ decays in the Standard Model and beyond
• Semileptonic decays $B_c\to ({\eta }_c,J/\psi )l{\bar{\nu }}_l$ in the "PQCD + Lattice" approach
• Phenomenology of $b\to c\tau \bar{\nu }$ decays in a scalar leptoquark model
• Global fit to $b\to c\tau \nu$ anomalies as of Spring 2024
• Probing New Physics with $\bar{B}\to \rho (770){\ell }^{-}{\bar{\nu }}_{\ell }$ and $\bar{B}\to a_1(1260){\ell }^{-}{\bar{\nu }}_{\ell }$
• R-parity violating solutions to the $R_{D^{(\ast )}}$ anomaly and their GUT-scale unifications
• Non-resonant new physics search at the LHC for the $b\to c\tau \nu$ anomalies
• Review of Semileptonic $B$ Anomalies
• Precision Model-Independent Bounds from Global Analysis of $b\to c\ell \nu$ Form Factors
• Boosting vector leptoquark searches with boosted tops
• From B-meson anomalies to Kaon physics with scalar leptoquarks
• Revisiting the $B$-physics anomalies in $R$-parity violating MSSM
• Semileptonic decays $B/B_s\to (D^{(\ast )},D_s^{(\ast )})l{\nu }_l$ in the PQCD approach with the lattice QCD input
• Scalar Leptoquarks, Baryon Number Violation and Pati-Salam Symmetry
• Model-Independent Determination of $B_c^{+}\to {\eta }_c{\ell }^{+}\nu$ Form Factors
• Discriminating $B\to D^{\ast }\ell \nu$ form factors via polarization observables and asymmetries
• Collider signature of $U_1$ Leptoquark and constraints from $b\to c$ observables
• Studying the $b\to s{\ell }^{+}{\ell }^{-}$ anomalies and $(g-2{)}_{\mu }$ in $R$-parity violating MSSM framework with the inverse seesaw mechanism
• Muon $g-2$ in a $U(1)$-symmetric Two-Higgs-Doublet Model
• Search for an invisible $Z^{\prime }$ in a final state with two muons and missing energy at Belle II
• A Complete Framework for Tau Polarimetry in $B\to D^{(\ast )}\tau \nu$ Decays
• Tests of the Standard Model in $B\to D\ell {\nu }_{\ell }$, $B\to D^{\ast }\ell {\nu }_{\ell }$ and $B_c\to J/\psi \ell {\nu }_{\ell }$
• Analysing the charged scalar boson contribution to the charged-current $B$ meson anomalies
• Coup de grace to the charged Higgs solution of $P_5^{\prime }$ and $R_{D^{(\ast )}}$ discrepancies
• Prospects for $B_c^{+}$ and $B^{+}\to {\tau }^{+}{\nu }_{\tau }$ at FCC-ee
• NLO QCD corrections to inclusive semitauonic weak decays of heavy hadrons up to $1/m_b^3$
• Implication of $R_{D^{(\ast )}}$ anomalies on semileptonic decays of ${\Sigma }_b$ and ${\Omega }_b$ baryons
• Phenomenology of TeV-scale scalar Leptoquarks in the EFT
• Scotogenic Dirac neutrino mass models embedded with leptoquarks: one pathway to address the flavor anomalies and the neutrino masses together
• Search for pair-produced vector-like leptons in final states with third-generation leptons and at least three b quark jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Measurement of the branching fraction ratios $R(D^{+})$ and $R(D^{\ast +})$ using muonic $\tau$ decays
• $\bar{B}\to D^{(\ast )}\ell \bar{X}$ decays in effective field theory with massive right-handed neutrinos
• Right-handed interactions in puzzling $B$-decays
• Implication of $b\to c\tau \nu$ flavor anomalies on $B_s\to D_s^{\ast }\tau \nu$ decay observables
• Lepton flavour violation in rare ${\Lambda }_b$ decays
• Leptoquarks and Real Singlets: A Richer Scalar Sector Behind the Origin of Dark Matter
• Angular and polarization observables for Majorana-mediated B decays with effective interactions
• Semileptonic decays of $B_c$ meson to $P$-wave charmonium states
• First Measurement of the Absolute Branching Fraction of $\Lambda \to p{\mu }^{-}{\bar{\nu }}_{\mu }$
• New physics footprints in the angular distribution of $B_s\to D_s^{\ast }(\to D_s\gamma ,D_s\pi )\tau \nu$ decays
• Measurement of the $D^{\ast }$ longitudinal polarization in $B^0\to D^{\ast -}{\tau }^{+}{\nu }_{\tau }$ decays
• First Measurement of $R(X_{\tau /\ell })$ as an Inclusive Test of the $b\to c\tau \nu$ Anomaly
• $b\to c\tau \bar{\nu }$ decays in supersymmetry with $R$-parity violation
• Implications for the $\Delta A_{FB}$ anomaly in ${\bar{B}}^0\to D^{\ast +}{\ell }^{-}\bar{\nu }$ using a new Monte Carlo Event Generator
• Probing New Physics Signals with Symmetry-Restored Yukawa Textures
• The ratio $\mathcal{R}(D_s)$ for $B_s\to D_s\ell {\nu }_{\ell }$ by using the QCD light-cone sum rules within the framework of heavy quark effective field theory
• Scouring meson decays for true muonium
• Leptoquarks in Flavour Physics
• Perspectives and Outlook from HEP Window on the Universe
• Search for heavy particles in the $b$-tagged dijet mass distribution with additional $b$-tagged jets in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS experiment
• Baryonic heavy-to-light form factors induced by tensor current in light-front approach
• Probing New Physics in light of recent developments in $b\to c\ell \nu$ transitions
• New physics in the angular distribution of $B_c^{-}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){\tau }^{-}(\to {\pi }^{-}{\nu }_{\tau }){\bar{\nu }}_{\tau }$ decay
• Extra gauge bosons and lepton flavor universality violation in ${\rm Y}$ and $B$ meson decays
• Radiative Semileptonic $\bar{B}$ Decays
• Test of lepton flavor universality with measurements of $R(D^{+})$ and $R(D^{\ast +})$ using semileptonic $B$ tagging at the Belle II experiment
• Singlet vector leptoquark model facing recent LHCb and BABAR measurements
• Precise test of lepton flavour universality in $W$-boson decays into muons and electrons in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Analysis of $b\to c\tau {\bar{\nu }}_{\tau }$ anomalies using weak effective Hamiltonian with complex couplings
• Rare decays of b hadrons
• Third-Family Lepton-Quark Fusion
• Search for pair production of scalar and vector leptoquarks decaying to muons and bottom quarks in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Search for charged-lepton-flavour violating $\mu \tau qt$ interactions in top-quark production and decay in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector at the LHC
• Semileptonic baryon decays ${\Xi }_b\to {\Xi }_c{\ell }^{-}{\bar{\nu }}_{\ell }$ in perturbative QCD
• Search for opposite sign muon-tau pair and a b-jet at LHC in the context of flavor anomalies
• Evidence for $B^{-}\to D^{\ast \ast 0}{\tau }^{-}\overline{{\nu }_{\tau }}$ decays
• Angular analysis of $\bar{B}\to D_2^{\ast }(\to D\pi )\ell \bar{\nu }$ decay and new physics
• Testing Lepton Flavour Universality in ${\rm Y}(4S)$ Decays
• Generic tests of CP-violation in high-$p_{\text{T}}$ multi-lepton signals at the LHC and beyond
• $B$ anomalies in the nonminimal universal extra dimension model
• Electric Dipole Moments as Probes of $B$ Anomaly
• Explaining the $\mathcal{R}(D)$ and $\mathcal{R}(D^{\ast })$ Anomalies in the $B-L$ Supersymmetric Standard Model with Inverse Seesaw
• Flavour anomalies meet flavour symmetry
• Explaining B decays anomalies in SUSY models
• Status of G2HDM with right handed neutrino coupling in the light of $b\to c\tau \nu$ anomalies
• Exploring the $\tau$ polarization in $B\to X\tau \bar{\nu }$ along different axes
• Flavour Physics from Present to Future Colliders
• Prospects for $B_c^{+}\to {\tau }^{+}{\nu }_{\tau }$ at FCC-ee
• Delving into new physics in semileptonic $b\to c\tau \bar{\nu }$ transitions
• Probing new physics at the LHC with $\mathrm{b}\tau \nu$ final states
• Neutron decay into a Dark Sector via Leptoquarks
• Hint of a new scalar interaction in LHCb data?
• Probing Light Scalars and Vector-like Quarks at the High-Luminosity LHC
• Searches for $B^0\to K^{+}{\pi }^{-}{\tau }^{+}{\tau }^{-}$ and $B_s^0\to K^{+}{K}^{-}{\tau }^{+}{\tau }^{-}$ decays
• Addressing the $R_{\tau /\mu ,e}\left(D^{(\ast )}\right)$ puzzle through New Physics four-fermion operators and their impact on ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ decay
• Closing the Gap on $R_{D^{\ast }}$ by including longitudinal effects
• Predictions for ${\Lambda }_b\to {\Lambda }_c\tau \bar{\nu }$ in BLSSM with Inverse seesaw
• Measurement of high-mass $t\bar{t}{\ell }^{+}{\ell }^{-}$ production and lepton flavour universality-inspired effective field theory interpretations at $\sqrt{s}=13$ TeV with the ATLAS detector
• Weakly supervised anomaly detection with event-level variables
• Search for heavy neutral resonances decaying to tau lepton pairs in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Flavor Anomalies and Quark-Lepton Unification
• Leveraging intermediate resonances to probe CP violation at colliders
• A self-calibrating, double-ratio method to test tau lepton universality in W boson decays at the LHC
• Rare B, D and K decays, radiative and electroweak penguin decays, including constraints on $V_{td}/V_{ts}$ and ${\epsilon }^{\prime }/\epsilon$: Summary of CKM 2018 working group 3
• Lepton universality tests and searches for new physics in charged current decays at Belle II
• The Angular Observables of ${\Lambda }_b\to {\Lambda }_c(\to {\Lambda }^0{\pi }^{+}){\tau }^{-}(\to {\pi }^{-}{\nu }_{\tau }){\bar{\nu }}_{\tau }$ within the Paradigm of FCCC Anomalies