News on PHOTOS Monte Carlo: γ * → π + π − (γ) and K ± → π + π − e ± ν(γ)

Measurement of Γ ( K S → π + π − ( γ ) ) / Γ ( K S → π 0 π 0 )

We have measured the ratio R S = Γ(KS → π π(γ))/Γ(KS → π π) with the KLOE detector at the DAΦNE ee collider. This measurement is fully inclusive with respect to the ππγ final state. The sample of over 10 two-pion decays of tagged KS mesons allows a statistical error as low as ∼ 0.1% to be obtained. The accuracy is limited by systematic uncertainties, which are estimated primarily from data. We ...

η → π + π − π 0 γ in Chiral Perturbation Theory

Reanalysis of CP Violation in K L → π + π − γ

We present a reanalysis of direct CP violation in the decay K L → π + π − γ. We point out an existing discrepancy between the theoretical and experimental definitions of ǫ ′ +−γ. Adopting the experimental definition of ǫ ′ +−γ , we estimate that ǫ ′ +−γ /ǫ could be as large as a few times 10 −4 both within the standard model and beyond. We discuss these estimates in detail and we also show how ...

0 Determination of γ from B̄ 0 → K − π + , π − π + Decays

We show that large electroweak penguin effects invalidate previously suggested methods to constraint and to determine the CP violating phase γ of the KM matrix using B̄0 → K−π+, π−π+ and B → K̄0π− decays. We obtain new results on the constraint and the determination of γ. It is found that present central values of experimental data on these decays exclude the range between 0.57 and 0.87 for γ whi...

2 00 2 CP - violation in K S , L → π + π − γ and K S , L → π + π − e + e − decays

The dependence of KS,L → ππγ decay probabilities on photon polarization is calculated. The phases of terms of amplitude that arise from the pion-pion interaction are obtained by using a simple realistic model of pion-pion interaction via virtual ρ-meson, instead of the ChPT. The results are compared with those of other authors and the origin of the discrepancies is explained. It is shown that t...