Complete analysis of all $B\to \pi K$ decays

Abstract

The Standard Model (SM) predicts that $\Delta A_{\mathrm{CP}}$, the difference between the direct CP asymmetries for the modes $B^{+}\to {\pi }^0{K}^{+}$ and $B^0\to {\pi }^{-}{K}^{+}$ that are related by weak isospin, should be close to zero. There has been a recent claim by the LHCb Collaboration that the measured value of $\Delta A_{\mathrm{CP}}$ shows an uncomfortable tension with the SM prediction, almost at the $8\sigma$ level. Motivated by this claim, we critically re-examine the data on all the $B\to \pi K$ modes, including the CP asymmetries and CP-averaged branching fractions. From a combined Bayesian analysis with the topological amplitudes and their phases as the free parameters, we find that the best-fit region has a large overlap with the parameter space favoured in the SM, albeit with some enhancement for the electroweak penguin and the colour-suppressed tree amplitudes, consistent with the findings of earlier studies. We find that in this SM-like region, $\Delta A_{\mathrm{CP}}$ is more than 5$\sigma$ away from zero and the tension with the global average, as well as the LHCb result, is within $2\sigma$. Thus we conclude that there is not yet enough motivation to go beyond the SM.

31 pages, 7 captioned figures. Analysis modified from v1. Accepted for publication in Physical Review D

References in corpus (19)

• Measurement of CP Asymmetries and Branching Fractions in Charmless Two-Body B-Meson Decays to Pions and Kaons
• Measurements of Direct CP-Violating Asymmetries in Charmless Decays of Bottom Baryons
• Is There Still a B -> pi K Puzzle?
• Rate and CP-asymmetry sum rules in $B\to K\pi$
• Resolving B-CP Puzzles in QCD Factorization
• Glauber gluons in spectator amplitudes for $B\to \pi M$ decays
• Searching For New Physics With B to K pi Decays
• Revisiting B\toπK, πK^{\ast} and ρK decays: CP violations and implication for New Physics
• Observation of $CP$ violation in two-body $B_{(\mathrm{s})}^0$-meson decays to charged pions and kaons
• Analytic Resolution of Puzzle in $B\to K\pi$ decays
• New physics in $B\to \pi \pi$ and $B\to \pi K$ decays
• Is there a non-Standard-Model contribution in non-leptonic b -> s decays?
• Measurement of CP violation in the decay $B^{+}\to K^{+}{\pi }^0$
• Axion-like particles resolve the $B\to \pi K$ and g-2 anomalies
• Diagnostic for new physics in $B\to \pi K$ decays
• Patterns of New Physics in B Decays
• First search for direct $CP$-violating asymmetry in $B^0\to K^0{\pi }^0$ decays at Belle II
• Measurements of branching fractions and direct $CP$-violating asymmetries in $B^+ \to K^+ π^0~\mbox{and}~π^+ π^0$ decays using 2019 and 2020 Belle II data
• Measurements of branching fractions and direct CP asymmetries in $B^0\to K^{+}{\pi }^{-}$, $B^{+}\to K_{\mathrm{S}}^0{\pi }^{+}$ and $B^0\to {\pi }^{+}{\pi }^{-}$ using 2019 and 2020 data

Cited by in corpus (2)

• Probing intractable beyond-standard-model parameter spaces armed with Machine Learning
• Polarisation fractions in $B\to V_1{V}_2$: U-Spin constraints and new physics signatures