K pi form factors, final state interactions and D+ -> K- pi+ pi+ decays

We present a model for the decay $D^+to K^-pi^+pi^+$. The weak interaction part of this reaction is described using the effective weak Hamiltonian in the factorisation approach. Hadronic final state interactions are taken into account through the $Kpi$ scalar and vector form factors fulfilling analyticity, unitarity and chiral symmetry constraints. Allowing for a global phase difference between the $S$ and $P$ waves of $-65^circ$, the Dalitz plot of the $D^+to K^-pi^+pi^+$ decay, the $Kpi$ invariant mass spectra and the total branching ratio due to $S$-wave interactions are well reproduced.

Linear Sigma Model predictions for V->Sgamma and S->Vgamma decays

The radiative decays $Vto Sgamma$ and $Sto Vgamma$ with $V=rho, omega, phi$ and $S=a_0, sigma, f_0$ are calculated within the framework of the Linear Sigma Model. Current experimental data on the $phito f_0gamma$ and $rhotosigmagamma$ branching ratios and the ratio $Gamma(phito f_0gamma)/Gamma(phito a_0gamma)$ are satisfactorily accommodated in our approach. We also estimate the decay widths of the $f_0,a_0torhogamma,omegagamma$ transitions. All the processes considered are of interest for ongoing experimental programs in Frascati, Julich and Novosibirsk.