Exploring $$B\rightarrow \pi \pi , \pi K$$ B → π π , π K decays at the high-precision frontier

Abstract

The system offers a powerful laboratory to probe strong and weak interactions. Using the isospin symmetry, we determine hadronic parameters from data where new measurements of direct CP violation in resolve a discrete ambiguity. With the help of the SU (3) flavour symmetry, the parameters can be converted into their counterparts, thereby allowing us to make predictions of observables. A particularly interesting decay is as it exhibits mixing-induced CP violation. Using an isospin relation, complemented with a robust SU (3) input, we calculate correlations between the direct and mixing-induced CP asymmetries of , which are the theoretically cleanest probes. Interestingly, they show tensions with respect to the Standard Model. Should this puzzle originate from New Physics, electroweak penguins offer an attractive scenario for new particles to enter. We present a strategy to determine the parameters characterising these topologies and obtain the state-of-the-art picture from current data. In the future, this method will allow us to reveal the dynamics and to obtain insights into the electroweak penguin sector with unprecedented precision.

Correlating ε′/ε with hadronic B decays via Crivellin1, Groß2, Pokorski3 et al. 2020Phys. Rev. D39280View full textAdd to dashboardCite

“…Interestingly, there are also tensions between theory and data concerning CP violation in hadronic B meson decays, including the long-standing B → Kπ puzzle [20][21][22][23][24][25]. Recently, LHCb data [26] increased this tension [27,28], and also the newly measured CP asymmetry in B s → K þ K − [26] points towards additional sources of CP violation, renewing the theoretical interest in these decays [29,30]. Like for ϵ 0 =ϵ, both CP and isospin violation are in general required for solving this tension.…”

Exploring New Physics in $B \rightarrow \pi K$ Decays

“…The result is illustrated in Fig. 3(a) [18]. Therefore, the green band is the one that comes from the isospin analysis and again, the sum rule prediction and the current data result are shown.…”

“…We can have 4 different combinations between the amplitudes A 00 andĀ 00 , which means that we can get 4 different angles φ 00 . As a result, we obtain four cases for the S π 0 K s asymmetry and this leads to four different branches in the A π 0 K s − S π 0 K s plane [18]. Fig.…”

“…2(e)-(f), there are also the values of the CP asymmetries for the current data. The vertical red band on these plots refers to the prediction coming from the sum rule [18].…”

On the importance of NNLO QCD and isospin-breaking corrections in $$\varepsilon '/\varepsilon $$

“…If confirmed by new RBC-UKQCD analysis this would turn out to be one of the largest anomalies in flavour physics present in a single observable and comparable to the anomaly in the flavour conserving (g − 2) µ . Moreover, this would be presently the only significant anomaly as far as CP-violation is concerned with the possible exception of the one present in B → πK decays [44], as recently reviewed in [45][46][47][48].…”