A Challenge to Lepton Universality in B Meson Decays

Abstract

One of the key assumptions of the Standard Model of fundamental particles is that the interactions of the charged leptons, namely electrons, muons, and taus, differ only because of their different masses. While precision tests comparing processes involving electrons and muons have not revealed any significant violation of this assumption, recent studies involving the higher-mass tau lepton have resulted in observations that challenge lepton universality at the level of four standard deviations. A confirmation of these results would point to new particles or interactions, and could have profound implications for our understanding of particle physics.

10 pages, 7 figures. Accepted for publication in Nature

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• Anomalies in Bottom from new physics in Top
• Semitauonic $b$-hadron decays: A lepton flavor universality laboratory
• The Mu-MASS (MuoniuM lAser SpectroScopy) experiment
• Implications of scalar and tensor explanations of $R_{D^{(\ast )}}$
• $b\to c\tau \nu$ 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
• Prospects for Measurements with Strange Hadrons at LHCb
• Direct CP violation in beauty and charm hadron decays
• R-parity violating solutions to the $R_{D^{(\ast )}}$ anomaly and their GUT-scale unifications
• Signature of Lepton flavor universality violation in $B_s\to D_s\tau \nu$ semileptonic decays
• Opportunities for lattice QCD in quark and lepton flavor physics
• CP asymmetry in $\tau \to K_S\pi {\nu }_{\tau }$ decays within the Standard Model and beyond
• $B$-decay anomalies and scalar leptoquarks in unified Pati-Salam models from noncommutative geometry
• Model-Independent Determination of $B_c^{+}\to {\eta }_c{\ell }^{+}\nu$ Form Factors
• Impact of vector new physics couplings on $B_s\to (K,K^{\ast })\tau \nu$ and $B\to \pi \tau \nu$ decays
• Search for narrow resonances in the b-tagged dijet mass spectrum in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Future Experimental Improvement for the Search of LNV Process in $e\mu$ Sector
• $D^{\ast }$ Polarization as an Additional Constraint on New Physics in the $b\to c\tau {\bar{\nu }}_{\tau }$ Transition
• Form-factor-independent test of lepton universality in semileptonic heavy meson and baryon decays
• Probing New Physics Signals with Symmetry-Restored Yukawa Textures
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• A Challenge to Lepton Universality in B Meson Decays
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• Exploring the flavour structure of the high-scale MSSM
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• Study of Nonstandard Interactions in Rare Decays of Hyprons with Missing Energy