# A challenge to lepton universality in B-meson decays

@article{Ciezarek2017ACT,
title={A challenge to lepton universality in B-meson decays},
author={Gregory Max Ciezarek and M. Franco Sevilla and Brian Hamilton and Robert Victor Kowalewski and Thomas Kuhr and Vera L{\"u}th and Yutaro Sato},
journal={Nature},
year={2017},
volume={546},
pages={227-233}
}
• Published 6 March 2017
• Physics
• Nature
One of the key assumptions of the standard model of particle physics is that the interactions of the charged leptons, namely electrons, muons and taus, differ only because of their different masses. Whereas precision tests comparing processes involving electrons and muons have not revealed any definite violation of this assumption, recent studies of B-meson decays involving the higher-mass tau lepton have resulted in observations that challenge lepton universality at the level of four standard…
66 Citations
A challenge to lepton universality in B meson decays
• V. Lüth
• Physics
Hyperfine Interactions
• 2018
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
B decay anomalies at LHCb
The LHCb collaboration has provided a plethora of precise measurements of flavour observables in the last years. In the B meson sector some of these results show consistent deviations from Standard
Opportunities for Lattice QCD in quark and lepton flavor physics
• Physics
The European Physical Journal A
• 2019
Abstract.This document is one of a series of white papers from the USQCD Collaboration. Here, we discuss opportunities for Lattice QCD in quark and lepton flavor physics. New data generated at Belle
Search for flavour anomalies at LHCb: decay-time-dependent CP violation in → &( (& and Lepton Universality in → (∗)&
The Standard Model (SM) of Particle Physics is a very successful theory, but it leaves some important questions unanswered. One long-standing mystery is the so called flavour structure, consisting on
Measurement of Top Quark Mass and Production Cross-Section using tt-bar pairs with Semi-Leptonic Decay Channel
A measurement of the tt̄ production cross section at √ s = 13 TeV is presented using proton-proton collisions, corresponding to an integrated luminosity of 2.2 fb−1, collected with the CMS detector
Semitauonic b -hadron decays: A lepton flavor universality laboratory
• Physics
Reviews of Modern Physics
• 2022
The study of lepton flavor universality violation (LFUV) in semitauonic $b$-hadron decays has become increasingly important in light of longstanding anomalies in their measured branching fractions,
D * Polarization as an Additional Constraint on New Physics in the b → cτ ν ¯ τ Transition
• Physics
• 2020
Measurements of the branching fractions of the semileptonic decays $B\to D^{(*)}\tau\bar\nu_\tau$ and $B_c\to J/\psi\tau\bar\nu_\tau$ systematically exceed the Standard Model (SM) predictions,
Future prospects for exploring present day anomalies in flavour physics measurements with Belle II and LHCb
• Physics
• 2017
A range of flavour physics observables show tensions with their corresponding Standard Model expectations: measurements of leptonic flavour-changing neutral current processes and ratios of
CP asymmetry in τ→KSπντ decays within the standard model and beyond
• Physics
Physical Review D
• 2019
Motivated by the 2.8σ discrepancy observed between the BABAR measurement and the standard model prediction of the CP asymmetry in τ→KSπντ decays, as well as the prospects of future measurements at

## References

SHOWING 1-10 OF 143 REFERENCES
A challenge to lepton universality in B meson decays
• V. Lüth
• Physics
Hyperfine Interactions
• 2018
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
Implications of lepton flavor universality violations in B decays.
• Physics
Physical review letters
• 2012
Present measurements of b→cτν and b→uτν transitions differ from the standard model predictions of lepton flavor universality by almost 4σ, and an effective field theory analysis shows that minimal flavor violating models are not preferred as an explanation, but are not yet excluded.
Exclusive semileptonic heavy meson decays including lepton mass effects
• Physics
• 1990
We discuss the exclusive semi-leptonic (s.l.) bottom meson decaysB→D(D*)+l+v where we include non-zero lepton mass effects in the kinematics and dynamics. We develop the general formalism for the
Physics with tau-leptons
The ? lepton and the third family.- Experimental aspects.- The static properties of the ?.- Electroweak physics at the Z0 pole.- Strong interactions in ? decays.- ? physics at hadron colliders.- The
Charged Higgs effects on exclusive semi-tauonicB decays
AbstractWe study effects of charged Higgs boson exchange in theB semileptonic decays $$\bar B \to D^{(*)} \tau \bar v_\tau$$ . Both branching ratio and τ polarization are examined. We use the recent
Measurement of the parameter ξ '' in polarized muon decay and implications on exotic couplings of the leptonic weak interaction
• Physics
• 2014
The Michel parameter xi" has been determined from a measurement of the longitudinal polarization of positrons emitted in the decay of polarized and depolarized muons. The result, xi" = 0.981 +-
Search for pair-production of scalar leptoquarks
• Physics
• 2011
This article describes the search for pair production of scalar leptoquarks performed by the CMS collaboration using the data from the 2010 proton-proton run of the Large Hadron Collider at a center
Search for third generation scalar leptoquarks in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
A search for pair-produced third generation scalar leptoquarks is presented, using proton-proton collisions at √ s = 7 TeV at the LHC. The data were recorded with the ATLAS detector and correspond to