## CP violation and kaon-pion interactions in B --> K pi+ pi- decays

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El-Bennich, B.

Furman, A.

Kaminski, R.

Lesniak, L.

Loiseau, B.

Moussallam, B.

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##### Abstract

##### Description

We study CP violation and the contribution of the strong kaon-pion
interactions in the three body B --> K pi+ pi- decays. We extend our recent
work on the effect of the two-pion S- and P-wave interactions to that of the
corresponding kaon-pion ones. The weak amplitudes have a first term derived in
QCD factorization and a second one as a phenomenological contribution added to
the QCD penguin amplitudes. The effective QCD coefficients include the leading
order contributions plus next-to-leading order vertex and penguins corrections.
The matrix elements of the transition to the vacuum of the kaon-pion pairs,
appearing naturally in the factorization formulation, are described by the
strange K pi scalar (S-wave) and vector (P-wave) form factors. These are
determined from Muskhelishvili-Omnes coupled channel equations using
experimental kaon-pion T-matrix elements, together with chiral symmetry and
asymptotic QCD constraints. From the scalar form factor study, the modulus of
the K*_0(1430) decay constant is found to be (32 +/- 5) MeV. The additional
phenomenological amplitudes are fitted to reproduce the K pi effective mass and
helicity angle distributions, the B --> K*(892) pi branching ratios and the CP
asymmetries of the recent data from Belle and BaBar collaborations. We use also
the new measurement by the BaBar group of the phase difference between the B0
and B0bar decay amplitudes to K*(892) pi. Our predicted B+/- --> K*_0(1430)
pi+/-, K*_0(1430) --> K+/- pi-\+ branching fraction, (11.6 +/- 0.6) 10^{-6}, is
smaller than the result of the analyzes of both collaborations. For the neutral
B0 decays, the predicted value is (11.1 +- 0.5) 10^{-6}. In order to reduce the
large systematic uncertainties in the experimental determination of the B -->
K*_0(1430) pi branching fractions, a new parametrization is proposed.

Comment: 56 pages, 15 figures

Comment: 56 pages, 15 figures

##### Keywords

High Energy Physics - Phenomenology, High Energy Physics - Experiment