The pion scalar form factor along with all existing S-wave iso-scalar $pipi$-scattering phase shift data in the elastic region up to $1 {rm GeV}^2$ are applied for a determination of the $f_0(500)$ and $f_0(980)$ meson parameters $m_{f_0(500)}=(360pm
33){rm MeV}$, $Gamma_{f_0(500)}=(587pm 85){rm MeV}$ and $m_{f_0(980)}=(957pm77) {rm MeV}$, $Gamma_{f_0(980)}=(164pm142){rm MeV}$ in a model independent way.
New precise experimental information on $sigma_{tot}(e^+e^- to pi^+ pi^-)$ is transferred into the space-like region, by taking advantage of the analyticity. As a result a rigorous pion electromagnetic form factor behavior is obtained. The latter with some existing model predictions is compared.
By means of the universal unitary and analytic model of electromagnetic structure of hadrons the two-photon decay rates of P=pi^0, eta, eta mesons are determined in an alternative way from data on their transition form factors.
Unitary and analytic ten-resonance model of the nucleon electromagnetic (e.m.) structure with canonical normalizations and asymptotics is constructed on a four-sheeted Riemann surface. It describes well all existing experimental space-like and time-l
ike data on the nucleon e.m. form factors (ffs), including also FENICE (Frascati) results on the neutron, for the first time. This is achieved without any external constraints on the isovector spectral functions following from the piN-scattering data and pion e.m. ff behaviour through the unitarity condition. Just opposite, the model itself predicts a pronounced effect of the two-pion continuum on the isovector spectral functions revealing the strong enhancement of the left wing of the rho(770)-resonance close to two-pion threshold. The existence of the fourth excited state of the rho(770) meson with parameters mass and width equal to 2506 MeV and 700 MeV, respectively. The isoscalar spectral function behaviours are predicted by the presented model.
