Search for $B^{+}\to {\mu }^{+}{\nu }_{\mu }$ and $B^{+}\to {\mu }^{+}N$ with inclusive tagging

Abstract

We report the result for a search for the leptonic decay of $B^{+}\to {\mu }^{+}{\nu }_{\mu }$ using the full Belle data set of 711 fb${}^{-1}$ of integrated luminosity at the ${\rm Y}(4S)$ resonance. In the Standard Model leptonic $B$-meson decays are helicity and CKM suppressed. To maximize sensitivity an inclusive tagging approach is used to reconstruct the second $B$ meson produced in the collision. The directional information from this second $B$ meson is used to boost the observed $\mu$ into the signal $B$ meson rest-frame, in which the $\mu$ has a monochromatic momentum spectrum. Though its momentum is smeared by the experimental resolution, this technique improves the analysis sensitivity considerably. Analyzing the $\mu$ momentum spectrum in this frame we find $\mathcal{B}(B^{+}\to {\mu }^{+}{\nu }_{\mu })=\left(5.3\pm 2.0\pm 0.9\right)\times 10^{-7}$ with a one-sided significance of 2.8 standard deviations over the background-only hypothesis. This translates to a frequentist upper limit of $\mathcal{B}(B^{+}\to {\mu }^{+}{\nu }_{\mu })<8.6\times 10^{-7}$ at 90% CL. The experimental spectrum is then used to search for a massive sterile neutrino, $B^{+}\to {\mu }^{+}N$, but no evidence is observed for a sterile neutrino with a mass in a range of 0 - 1.5 GeV. The determined $B^{+}\to {\mu }^{+}{\nu }_{\mu }$ branching fraction limit is further used to constrain the mass and coupling space of the type II and type III two-Higgs-doublet models.

References in corpus (34)

• Asymptotic formulae for likelihood-based tests of new physics
• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of summer 2016
• Semileptonic Meson Decays in the Quark Model: An Update
• Sterile Neutrino Dark Matter
• Model-independent description of $B\to \pi l\nu$ decays and a determination of $|V_{ub}|$
• Constraints on Form Factors For Exclusive Semileptonic Heavy to Light Meson Decays
• A Measurement of the Branching Fraction for the Inclusive B --> X(s) gamma Decays with the Belle Detector
• Explaining B->Dτν, B->D*τνand B->τνin a 2HDM of type III
• The Belle II Core Software
• Search for heavy neutral leptons in events with three charged leptons in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Theory of Charmless Inclusive B Decays and the Extraction of V_{ub}
• A fresh look at the determination of |V_cb| from B-> D^* l nu
• Electron Identification in Belle
• Search for Neutral Heavy Leptons in a High-Energy Neutrino Beam
• Combined search for the Standard Model Higgs boson in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
• Radiative leptonic decays of B mesons in QCD
• Study of B --> pi l nu and B --> rho l nu Decays and Determination of |V_ub|
• Study of Exclusive B->X_u l nu Decays and Extraction of |V_{ub}| using Full Reconstruction Tagging at the Belle Experiment
• B -> X_u l nu decay distributions to order alpha_s
• Decay constants of heavy-light vector mesons from QCD sum rules
• Measurement of the decay $B\to D\ell {\nu }_{\ell }$ in fully reconstructed events and determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$
• Search for Exclusive Charmless Hadronic B Decays
• Model-Independent Extraction of $|V_{cb}|$ from $\bar{B}\to D^{\ast }\ell \overline{\nu }$
• Limits on the Mixing of Tau Neutrino to Heavy Neutrinos
• The Full Event Interpretation -- An exclusive tagging algorithm for the Belle II experiment
• Measurement of Branching Fractions for B->ππ, Kπand KK Decays
• Two-loop Corrections to the B to pi Form Factor from QCD Sum Rules on the Light-Cone and |V(ub)|
• B2BII - Data conversion from Belle to Belle II
• $B$ Meson Decay Constants $f_{B_c}$, $f_{B_s}$ and $f_B$ from QCD Sum Rules
• Search for the rare decay of $B^{+}\to {\ell }^{+}{\nu }_{\ell }\gamma$ with improved hadronic tagging
• Branching fraction measurement of B -> omega l nu decays
• Search for the Rare Leptonic Decays \boldmath{\Blnu} ($\ell =e,\mu$)
• Search for $B^{-}\to {\mu }^{-}{\bar{\nu }}_{\mu }$ Decays at the Belle Experiment
• Charged Higgs boson contribution to $B_q^{-}\to \ell \bar{\nu }$ and $\bar{B}\to (P,V)\ell \bar{\nu }$ in a generic two-Higgs doublet model

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• Muon Flavor Violation in Two Higgs Doublet Model with Extra Yukawa Couplings
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• First Simultaneous Determination of Inclusive and Exclusive $\left|V_{ub}\right|$
• Singlet vector leptoquark model facing recent LHCb and BABAR measurements
• The $B^{+}\to K^{+}\nu \bar{\nu }$ decay as a search for the QCD axion
• Enhanced $B_q\to \ell {\ell }^{\prime }$ and $B\to (K,\pi )\ell {\ell }^{\prime }$ in light of $(g-2{)}_{\mu }$
• Minimal U(1) two-Higgs-doublet models for quark and lepton flavour
• Measurement of the Ratio of Partial Branching Fractions of Inclusive $\overline{B}\to X_u\ell \overline{\nu }$ to $\overline{B}\to X_c\ell \overline{\nu }$ and the Ratio of their Spectra with Hadronic Tagging
• Study of $B^{+}\to {\mu }^{+}{\nu }_{\mu }$ decays at Belle and Belle II
• New results on inclusive $B\to X_u\ell \nu$ decay from the Belle experiment
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