Penguin pollution in $\beta$ and $\beta_s$

Abstract

The mixing-induced CP asymmetries in B d → J/ψK S and B s → J/ψφ are essential to detect or constrain new physics in the B d −B d and B s −B s mixing amplitudes, respectively. To this end one must control the penguin contributions to the decay amplitudes, which affect the extraction of fundamental CP phases from the measured CP asymmetries. Although the "penguin pollution" is doubly Cabibbo-suppressed, it could compete in size with current experimental errors. In this talk I present a calculation of the penguin contributions treating QCD effects with soft-collinear factorisation and compare method and results with the alternative approach employing flavour-SU(3) symmetry. As a novel feature, I present results for the penguin pollution in b → ccd modes.

Averages of b-hadron, c-hadron, and $$\tau $$ τ -lepton properties as of summer 2016

“…An independent result, d / d = (0.50 ± 1.38)% [195], was obtained by the D0 collaboration from their measurements of the single muon and same-sign dimuon charge asymmetries, under the interpretation that the observed asymmetries are due to CP violation in neutral B-meson mixing and interference. This indirect determination was called into question [196] and is therefore not included in the above average, as explained in Sect. 3.3.3 (see Footnote 17).…”

“…[234], the D0 collaboration extracts [195] values for A d SL and A s SL and their correlation coefficient, 17 as shown in Table 20. However, the various contributions to the total quoted errors from this analysis and from the external inputs are not given, so the adjustment of these results to different 17 In each impact parameter bin i the measured same-sign dimuon asymmetry is interpreted as [195] assumes λ = 1, but it has been demonstrated subsequently that λ ≤ 0.49 [196] Table 20 (B-factory average as the grey band, D0 measurements as the green ellipses, LHCb measurements as the blue ellipse) together with their two-dimensional average (red hatched ellipse). The red point close to (0, 0) is the Standard Model prediction of Refs.…”

“…Averages ofB 0 s decays to charmonium states are shown in Tables 195,196,197,198,199 and Figs. 161,162,163,164,165.…”

Summary of Working Group 4 : mixing and mixing-related $CP$ violation in the $B$ system

“…s → J/ψK + K − is expected to be dominated by the tree-level diagram, as the experimental precision on φ s improves it will become increasingly important to account for residual penguin pollution [9] in order to correctly interpret any agreement, or otherwise, with the theoretical prediction. The size of such effects can be controlled using a combination of B 0 s → J/ψK * 0 and B 0 → J/ψρ decays, which are related by U-spin symmetry and in the limit of zero non-factorizable SU(3) breaking are sensitive to the same, universal, penguin amplitudes and phases.…”

Summary of CKM 2016 Working Group 4 : mixing and mixing-related $CP$ violation in the $B$ system

“…LHCb has also measured φ s using B 0 s → ψ(2S)φ decays, obtaining 0.23 +0.29 −0.28 ± 0.02 rad. While B 0 s → J/ψK + K − is expected to be dominated by the tree-level diagram, as the experimental precision on φ s improves it will become increasingly important to account for residual penguin pollution [9] in order to correctly interpret any agreement, or otherwise, with the theoretical prediction. The size of such effects can be controlled using a combination of B 0 s → J/ψK * 0 and B 0 → J/ψρ decays, which are related by U-spin symmetry and in the limit of zero non-factorizable SU(3) breaking are sensitive to the same, universal, penguin amplitudes and phases.…”