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The B -> pi pi,pi K Puzzles in the Light of New Data: Implications for the Standard Model, New Physics and Rare Decays

Andrzej J. Buras·Robert Fleischer·Stefan Recksiegel·Felix Schwab
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Abstract

Recently, we developed a strategy to analyse the B -> pi pi,pi K data. We found that the B -> pi pi measurements can be accommodated in the Standard Model (SM) through large non-factorizable effects. On the other hand, our analysis of the ratios R_c and R_n of the CP-averaged branching ratios of the charged and neutral B -> pi K modes, respectively, suggested new physics (NP) in the electroweak penguin sector, which may have a powerful interplay with rare decays. In this paper, we confront our strategy with recent experimental developments, addressing also the direct CP violation in B_d -> pi^-+ K^+-, which is now an established effect, the relation to its counterpart in B^+- -> pi^0 K^+-, and the first results for the direct CP asymmetry of B_d -> pi^0 pi^0 that turn out to be in agreement with our prediction. We obtain hadronic B -> pi pi,pi K parameters which are almost unchanged and arrive at an allowed region for the unitarity triangle in perfect accordance with the SM. The ``B -> pi K puzzle'' persists, and can still be explained through NP, as in our previous analysis. In fact, the recently observed shifts in the experimental values of R_c and R_n have been predicted in our framework on the basis of constraints from rare decays. Conversely, we obtain a moderate deviation of the ratio R of the CP-averaged B_d -> pi^-+ K^+- and B^+- -> pi^+- K rates from the current experimental value. However, using the emerging signals for B^+- -> K^+- K modes, this effect can be attributed to certain hadronic effects, which have a minor impact on R_c and do not at all affect R_n. Our results for rare decays remain unchanged.

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Andrzej J. Buras, Robert Fleischer, Stefan Recksiegel, Felix Schwab. 2004-11-08. The B -> pi pi,pi K Puzzles in the Light of New Data: Implications for the Standard Model, New Physics and Rare Decays. https://arxiv.org/abs/hep-ph/0410407

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