Precision measurement of   $\sigma(e^+e^-\rightarrow\pi^+\pi^-\gamma)/\sigma(e^+e^-\rightarrow   \mu^+\mu^-\gamma)$ and determination of the $\pi^+\pi^-$ contribution to the   muon anomaly with the KLOE detector
  We have measured the ratio $\sigma(e^+e^-\rightarrow\pi^+\pi^-\gamma)/\sigma(e^+e^-\rightarrow \mu^+\mu^-\gamma)$, with the KLOE detector at DA$\Phi$NE for a total integrated luminosity of $\sim$ 240 pb$^{-1}$. From this ratio we obtain the cross section $\sigma(e^+e^-\rightarrow\pi^+\pi^-)$. From the cross section we determine the pion form factor $|F_\pi|^2$ and the two-pion contribution to the muon anomaly $a_\mu$ for $0.592<M_{\pi\pi}<0.975$ GeV, $\Delta^{\pi\pi} a_\mu$= $({\rm 385.1\pm1.1_{stat}\pm2.7_{sys+theo}})\times10^{-10}$. This result confirms the current discrepancy between the Standard Model calculation and the experimental measurement of the muon anomaly. 
KLOE and KLOE-2 Collaborations: D. Babusci, D. Badoni, I.   Balwierz-Pytko, G. Bencivenni, C. Bini, C. Bloise, F. Bossi, P. ...
hep-ex hep-ph