Anatomy of prominent B and K decays and signatures of CP-violating new physics in the electroweak penguin sector

Buras, Andrzej J.; Fleischer, Robert; Recksiegel, Stefan; Schwab, Félix

doi:10.1016/j.nuclphysb.2004.07.009

Cited by 222 publications

(182 citation statements)

References 170 publications

(233 reference statements)

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“…In the present work, it is the dispersive part of the rescattering from DD to ππ via annihilation that plays the role for the enhancement of π 0 π 0 and suppression of π + π − . also [70] for the same conclusion reached in a different context). It is worth mentioning that the isospin analyses of B → ππ decay data in [71] and [72] all indicate that given the allowed region of the π 0 π 0 branching ratio, there is practically no constraints on π 0 π 0 direct CP violation from BaBar and/or Belle data.…”

Section: B → ππ Decays a Short-distance Contributions And Experimsupporting

confidence: 67%

Final state interactions in hadronicBdecays

2005

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There exist many experimental indications that final-state interactions (FSIs) may play a prominent role not only in charmful B decays but also in charmless B ones. We examine the final-state rescattering effects on the hadronic B decay rates and their impact on direct CP violation. The color-suppressed neutral modes such as B 0 → D 0 π 0 , π 0 π 0 , ρ 0 π 0 , K 0 π 0 can be substantially enhanced by long-distance rescattering effects. The direct CP -violating partial rate asymmetries in charmless B decays to ππ/πK and ρπ are significantly affected by final-state rescattering and their signs are generally different from that predicted by the short-distance approach. For example, direct CP asymmetry in B 0 → ρ 0 π 0 is increased to around 60% due to final state rescattering effects whereas the short-distance picture gives about 1%. Evidence of direct CP violation in the decay B 0 → K − π + is now established, while the combined BaBar and Belle measurements of B 0 → ρ ± π ∓ imply a 3.6σ direct CP asymmetry in the ρ + π − mode. Our predictions for CP violation agree with experiment in both magnitude and sign, whereas the QCD factorization predictions (especially for ρ + π − ) seem to have some difficulty with the data. Direct CP violation in the decay B − → π − π 0 is very small ( < ∼ 1%) in the Standard Model even after the inclusion of FSIs. Its measurement will provide a nice way to search for New Physics as in the Standard Model QCD penguins cannot contribute (except by isospin violation). Current data on πK modes seem to violate the isospin sum rule relation, suggesting the presence of electroweak penguin contributions. We have also investigated whether a large transverse polarization in B → φK * can arise from the final-state rescattering of D ( * )D ( * ) s into φK * . While the longitudinal polarization fraction can be reduced significantly from short-distance predictions due to such FSI effects, no sizable perpendicular polarization is found owing mainly to the large cancellations occurring in the processes B → D * sD → φK * and B → D sD * → φK * and this can be understood as a consequence of CP and SU(3) [CPS] symmetry. To fully account for the polarization anomaly (especially the perpendicular polarization) observed in B → φK * , FSI from other states or other mechanism, e.g. the penguin-induced annihilation, may have to be invoked. Our conclusion is that the small value of the longitudinal polarization in V V modes cannot be regarded as a clean signal for New Physics.

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Section: B → ππ Decays a Short-distance Contributions And Experimsupporting

confidence: 67%

Final state interactions in hadronicBdecays

2005

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“…Shortly after these measurements were first made (in the early 2000s), it was noted that there was an inconsistency among them. This was referred to as the "B → πK puzzle" [1][2][3].…”

Section: Jhep01(2018)074mentioning

confidence: 99%

The B → πK puzzle revisited

Beaudry

Datta

London

et al. 2018

J. High Energ. Phys.

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For a number of years, there has been a certain inconsistency among the measurements of the branching ratios and CP asymmetries of the four B → πK decays. In this paper, we re-examine this B → πK puzzle. We find that the key unknown parameter is |C /T |, the ratio of color-suppressed and color-allowed tree amplitudes. If this ratio is large, |C /T | = 0.5, the SM can explain the data. But if it is small, |C /T | = 0.2, the SM cannot explain the B → πK puzzle -new physics (NP) is needed. The two types of NP that can contribute to B → πK at tree level are Z bosons and diquarks. Z models can explain the puzzle if the Z couples to right-handed uū and/or dd, with g dd R = g uu R . Interestingly, half of the many Z models proposed to explain the present anomalies in b → sµ + µ − decays have the required Z couplings to uū and/or dd. Such models could potentially explain both the b → sµ + µ − anomalies and the B → πK puzzle. The addition of a color sextet diquark that couples to ud can also explain the puzzle.

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“…One should also emphasize that the manner in which the LHT model goes beyond the MFV scenario differs from the frameworks studied in [34] and [35], where the modification of the flavour structure is connected dominantly to the third generation of quarks. Here, the new flavour violating interactions come simply from another sector that couples weakly to ordinary fermions and in principle all generations of mirror fermions can contribute to FCNC processes with equal strength.…”

Section: Jhep12(2006)003mentioning

confidence: 99%