Flavour (non-)Anomalies

Plots listing a cherry-picked sets of flavour anomalies. The top plots show lepton-universality tests. The second focuses on $b\to s\mu^+\mu^-$ measurements, while the following add more quantities of interest. Pick your favourite plot depending on what you want your focus is.

Each row shows the significance (blue dot) of a measurement described in the text above. For each entry, the SM expectation (orange diamond) is set to zero, the experimental and theory uncertainties are summed in quadrature and their sum is normalised to unity. The experimental value is then shifted and scaled accordingly. If a significance is given in the relevant publication, this value is used instead of the computed significance. In the left hand side plots, the significance is signed, in the right hand side it is not.

References

• $B^+\to K^+\mu^+\mu^-$: Average of Belle, CDF, BaBar, LHCb-PAPER-2014-006, LHCb-PAPER-2022-045, CMS vs Parrott, Bouchard, Davies (HPQCD), PRD 107 (2023) 014511.
• $B^+\to K^+e^+e^-$: LHCb-PAPER-2022-045 vs Parrott, Bouchard, Davies (HPQCD), PRD 107 (2023) 014511.
• $B^+\to K^+\nu\bar{\nu}$: World average by Belle II vs Parrott, Bouchard, Davies (HPQCD), PRD 107 (2023) 014511.
• $B_s^0\to\phi\ell^+\ell^-$: LHCb-PAPER-2021-014 and LHCb-PAPER-2024-032 vs Horgan, Liu, Meinel, Wingate via FLAVIO.
• $B^0_{(s)}\to\mu^+\mu^-$: HFlav for $B_s^0$ and LHC average by Allanach, Davighi for $B^0$ 2211.11766 vs flavio ran by Allanach, Davighi.
• $P'_5$: My own average of LHCb-PAPER-2020-002, LHCb-PAPER-2020-041, ATLAS'2018, CMS'2017, Belle'2016 versus Algueró et al., EPJC 83 (2023) 648.
• $R_K$, $R_{K^*}$: LHCb-PAPER-2022-045 vs Bordone, Isidori, Pattori.
• $R_{K_{\rm S}^0}$ and $R_K^{*+}$: LHCb-PAPER-2021-038 vs Bordone, Isidori, Pattori.
• $R_{K\pi\pi}$: LHCb-PAPER-2024-046 vs $1.00\pm0.01$.
• $R_{pK}$: LHCb-PAPER-2019-040 vs $1.00\pm0.01$.
• $g-2$: Fermilab muon $g-2$ (2025) vs Fermilab theory white paper (WP) update and vs BMW. The electron numbers are those of wikipedia (as of April 2021).
• $R(D), R(D^*)$: HFLAV numbers.
• $R(J/\psi)$: LHCb-PAPER-2017-035 vs Harrison, Davies, Lytle.
• $R(\Lambda_c^+)$: LHCb-PAPER-2021-044 vs Bernlochner, Ligeti, Robinson, Sutcliffe.
• ${\cal B}(B^+\to\tau^+\nu)$: PDG 2021 vs UTFit.
• $\Delta m_d,\,\Delta m_s$: LHCb-PAPER-2021-005 and PDG vs Di Luzio, Kirk, Lenz, Rauh.
• $Z A_{\rm FB}^{0,b}$: LEP EW group vs gFitter.
• $[1,6]$ intervals refer to dilepton mass squared ($q^2$) ranges in $\rm GeV^2$.
• Please note that the two error bars sum (in quadrature) to unity. Hence the smaller the experimental uncertainty becomes, the larger the theory uncertainty will look in comparison. Therefore one cannot easily compare uncertainties from several ovservables. For example the $R_K$ theory uncertainty looks larger than that on $R_{K^*}$, but this is due to the more precise measurement of $R_K$. Similarly the theory uncertainties on $B^0$ and $B_s^0\to\mu^+\mu^-$ look different because the $B_s^0$ measurement is much more precise.

Please report mistakes.

© CC BY 4.0 Patrick Koppenburg, 2024
Flavour Anomalies, https://www.nikhef.nl/~pkoppenb/anomalies.html. (cff file)
See also Patrick Koppenburg et al. (2016) Rare decays of b hadrons. Scholarpedia, 11(6):32643.

Code at https://gitlab.cern.ch/pkoppenb/bllsplots (needs CERN login).