Correlating Non-Resonant Di-Electron Searches at the LHC to the Cabibbo-Angle Anomaly and Lepton Flavour Universality Violation

Abstract

In addition to the existing strong indications for lepton flavour university violation (LFUV) in low energy precision experiments, CMS recently released an analysis of non-resonant di-lepton pairs which could constitute the first sign of LFUV in high-energy LHC searches. In this article we show that the Cabibbo angle anomaly, an (apparent) violation of first row and column CKM unitarity with $\approx 3\sigma$ significance, and the CMS result can be correlated and commonly explained in a model independent way by the operator $[Q_{\ell q}^{(3)}{]}_{1111}=({\bar{\ell }}_1{\gamma }^{\mu }{\sigma }^I{\ell }_1)({\bar{q}}_1{\gamma }_{\mu }{\sigma }^I{q}_1)$. This is possible without violating the bounds from the non-resonant di-lepton search of ATLAS (which interestingly also observed slightly more events than expected in the electron channel) nor from $R(\pi )=\pi \to \mu \nu /\pi \to e\nu$. We find a combined preference for the new physics hypothesis of $4.5\sigma$ and predict $1.0004<R(\pi )<1.0009$ (95\%~CL) which can be tested in the near future with the forthcoming results of the PEN experiment.

arXiv comment6 pages, 2 figures

References in corpus (60)

• Final Report of the Muon E821 Anomalous Magnetic Moment Measurement at BNL
• Dimension-Six Terms in the Standard Model Lagrangian
• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of summer 2016
• The anomalous magnetic moment of the muon in the Standard Model
• Test of lepton universality using $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• Evidence for an excess of B -> D(*) Tau Nu decays
• Test of lepton universality with $B^0\to K^{\ast 0}{\ell }^{+}{\ell }^{-}$ decays
• Measurement of an Excess of B -> D(*) Tau Nu Decays and Implications for Charged Higgs Bosons
• Measurement of the ratio of branching fractions $\mathcal{B}({\overline{B}}^0\to D^{\ast +}{\tau }^{-}{\overline{\nu }}_{\tau })/\mathcal{B}({\overline{B}}^0\to D^{\ast +}{\mu }^{-}{\overline{\nu }}_{\mu })$
• Angular analysis of the $B^0\to K^{\ast 0}{\mu }^{+}{\mu }^{-}$ decay using $3\,\mbox{fb}^{-1}$ of integrated luminosity
• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2018
• Differential branching fractions and isospin asymmetries of $B\to K^{(\ast )}{\mu }^{+}{\mu }^{-}$ decays
• Patterns of New Physics in $b\to s{\ell }^{+}{\ell }^{-}$ transitions in the light of recent data
• Hard Interactions of Quarks and Gluons: a Primer for LHC Physics
• Measurement of the ratio of the $B^0\to D^{\ast -}{\tau }^{+}{\nu }_{\tau }$ and $B^0\to D^{\ast -}{\mu }^{+}{\nu }_{\mu }$ branching fractions using three-prong $\tau$-lepton decays
• Flavour anomalies after the $R_{K^{\ast }}$ measurement
• Angular analysis and differential branching fraction of the decay $B_s^0\to \varphi {\mu }^{+}{\mu }^{-}$
• 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
• Search for new high-mass phenomena in the dilepton final state using 36 fb${}^{-1}$ of proton-proton collision data at $\sqrt{s}$ = 13 TeV with the ATLAS detector
• Interpreting Hints for Lepton Flavor Universality Violation
• Reduced hadronic uncertainty in the determination of $V_{ud}$
• Improved Calculation of Electroweak Radiative Corrections and the Value of V_ud
• B-decay discrepancies after Moriond 2019
• Towards the discovery of new physics with lepton-universality ratios of $b\to s\ell \ell$ decays
• Emerging patterns of New Physics with and without Lepton Flavour Universal contributions
• High-$p_T$ dilepton tails and flavour physics
• Radiative Corrections to Neutron and Nuclear Beta Decays Revisited
• $R_K$ and $R_{K^{\ast }}$ beyond the Standard Model
• Dispersive Evaluation of the Inner Radiative Correction in Neutron and Nuclear $\beta$-decay
• New Physics in $b\to s{\mu }^{+}{\mu }^{-}$ after the Measurement of $R_{K^{\ast }}$
• The Standard Model prediction for R_{e/mu}^{(pi,K)}
• Angular analysis of the decay B0 to K*0 mu mu from pp collisions at sqrt(s) = 8 TeV
• The CKM unitarity problem: A trace of new physics at the TeV scale?
• New Physics in $b\to s{\ell }^{+}{\ell }^{-}$ confronts new data on Lepton Universality
• Global fit to $b\to c\tau \nu$ transitions
• Joint lattice QCD - dispersion theory analysis confirms the quark-mixing top-row unitarity deficit
• Global Fit to Modified Neutrino Couplings and the Cabibbo-Angle Anomaly
• Constraints on Sterile Neutrinos in the MeV to GeV Mass Range
• Addendum to "Impact of polarization observables and $B_c\to \tau \nu$ on new physics explanations of the $b\to c\tau \nu$ anomaly"
• Beta decays as sensitive probes of lepton flavor universality
• ManeParse: a Mathematica reader for Parton Distribution Functions
• Improved measurement of the $π\rightarrow \mbox{e} ν$ branching ratio
• Standard Model $\mathcal{O}(\alpha )$ renormalization of $g_A$ and its impact on new physics searches
• Global Electroweak Fit and Vector-Like Leptons in Light of the Cabibbo Angle Anomaly
• Lessons from the $B^{0,+}\to K^{\ast 0,+}{\mu }^{+}{\mu }^{-}$ angular analyses
• $\gamma W$-box Inside-Out: Nuclear Polarizabilities Distort the Beta Decay Spectrum
• On lepton non-universality in exclusive $b\to s\ell \ell$ decays
• Revisiting the new-physics interpretation of the $b\to c\tau \nu$ data
• The Fermi constant from muon decay versus electroweak fits and CKM unitarity
• Cabibbo anomaly versus electroweak precision tests: An exploration of extensions of the Standard Model
• Explaining $b\to s{\ell }^{+}{\ell }^{-}$ and the Cabibbo Angle Anomaly with a Vector Triplet
• On the Statistical Treatment of the Cabibbo Angle Anomaly
• Searching for Lepton Flavour (Universality) Violation and Collider Signals from a Singly-Charged Scalar Singlet
• Combined Constraints on First Generation Leptoquarks
• Are the CKM anomalies induced by vector-like quarks? Limits from flavor changing and Standard Model precision tests
• Combined Explanation of the $Z\to b\bar{b}$ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, $\tau \to \mu \nu \nu$ and $b\to s{\ell }^{+}{\ell }^{-}$ Data
• Search for new non-resonant phenomena in high-mass dilepton final states with the ATLAS detector
• Muon $g-2$ and CKM Unitarity in Extra Lepton Models
• Limits on contact interactions and leptoquarks at HERA
• The role of non-universal $Z$ couplings in explaining the $V_{us}$ anomaly

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• The Forward-Backward Asymmetry in $B\to D^{\ast }\ell \nu$: One more hint for Scalar Leptoquarks?
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• A model with vectorlike fermions and $U(1{)}_X$ symmetry: CKM unitarity, $b\to s$ transitions, and prospect at Belle II
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