Determination of σ(e+e–→ π+π–) from radiative processes at DAΦNE

We have measured the cross section σ(e+e–→π+π–γ) with the KLOE detector at DAΦNE, at an energy W=Mφ=1.02 GeV. From the dependence of the cross section on \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$m(\pi^+\pi^{-})=\sqrt{W^2-2WE_\gamma}$\end{document}, where Eγ is the energy of the photon radiated from the initial state, we extract σ(e+e–→π+π–) for the mass range 0.35<m2(π+π–)<0.95 GeV2. From our result we extract the pion form factor and the hadronic contribution to the muon anomaly, aμ.