In principle, the extraction of α from B → ππ, ρπ, and ρρ decays is affected by NP effects in |Δ F|=1 transitions. In the presence of NP in the strong b &rarr d penguins, the decay amplitudes for B mesons decaying into ππ, ρπ, and ρρ are a simple generalization of the SM ones (given for example here): Assuming that NP modifies significantly only the "penguin" amplitude P without changing its isospin quantum numbers (i.e. barring large isospin-breaking NP effects), the only necessary modification amounts to distinguish the penguin complex parameters P and P, which come from the sum of SM and NP contributions in B and B decays and which bring in general different weak and strong phases. The procedure to extract α is the same as in the SM case but the expected bound is weaker due to the presence of two (four) extra parameter(s) for ππ and ρρ (ρπ).
(EPS) [JPG] |
Since NP effects in |ΔF|=2 are not included, this constraint has to be interpreted as a bound to α-φBd (see above) once it is used in the extension of the UT analysis including NP in |ΔF|=2.