ar X iv : h ep - p h / 00 12 32 3 v 1 2 3 D ec 2 00 0 27 S - matrix Bases and Relation between ππ - Scattering and Production Amplitudes

ar X iv : h ep - p h / 05 12 10 1 v 1 8 D ec 2 00 5 Hard spectator - scattering in B → ππ decays at NNLO ∗

We compute the 1-loop (NNLO) corrections to hard spectator-scattering in tree-dominated hadronic B decays. Depending on the values of hadronic input parameters the corrections are shown to have a significant impact on the B → ππ branching fractions.

ar X iv : h ep - p h / 06 12 05 2 v 1 5 D ec 2 00 6 Dispersive chiral approach to Meson - meson dynamics : Spectroscopy results for light scalars and precision studies

Dispersive approaches provide model independent description of meson-meson scattering. We first review here the use of dispersion relations to obtain a model independent unitarization of Chiral Perturbation Theory amplitudes, that establish the existence of light scalar mesons and whose leading 1/Nc behavior suggest they ahve a non q̄q dominant component. We also review the forward dispersion re...

ar X iv : h ep - p h / 04 05 11 8 v 1 1 3 M ay 2 00 4 Understanding I = 2 ππ Interaction

A correct understanding and description of the I = 2 ππ S-wave interaction is important for the extraction of the I = 0 ππ S-wave interaction from experimental data and for understanding the I = 0 ππ S-wave interaction theoretically. With t-channel ρ, f 2 (1270) exchange and the ππ → ρρ → ππ box diagram contribution, we reproduce the ππ isotensor S-wave and D-wave scattering phase shifts and in...

ar X iv : h ep - p h / 03 12 27 6 v 1 1 9 D ec 2 00 3 The a 0 K + K − - vertex in light cone QCD sum rules

ar X iv : h ep - p h / 03 10 08 2 v 1 7 O ct 2 00 3 Roy ’ s equations and the ππ experimental data

Roy’s equations are used to check if the scalar-isoscalar ππ scattering amplitudes fitted to experimental data fulfill crossing symmetry conditions. It is shown that the amplitudes describing the “down-flat” phase shift solution satisfy crossing symmetry below 1 GeV while the amplitudes fitted to the “up-flat” data do not. In this way the long standing ”up-down” ambiguity in the phenomenologica...