The mini-proceedings of the 15th Meeting of the Working Group on Rad. Corrections and MC Generators for Low Energies held in Mainz on April 11, 2014, are presented. These meetings, started in 2006, have as aim to bring together experimentalists and t
heorists working in the fields of meson transition form factors, hadronic contributions to $(g-2)_mu$ and the effective fine structure constant, and development of Monte Carlo generators and Radiative Corrections for precision e+e- and tau physics.
The mini-proceedings of the 14th Meeting of the Working Group on Rad. Corrections and MC Generators for Low Energies held in Frascati on September 13, 2013, as a satellite meeting of the PHIPSI13 conference in Rome, are presented. These meetings, sta
rted in 2006, have as aim to bring together experimentalists and theorists working in the fields of meson transition form factors, hadronic contributions to (g-2)_mu and the effective fine structure constant, and development of MonteCarlo generators and Radiative Corrections for precision e+e- and tau physics.
We have measured the cross section of the radiative process e+e- -> pi+pi-gamma with the KLOE detector at the Frascati phi-factory DAPHNE, from events taken at a CM energy W=1 GeV. Initial state radiation allows us to obtain the cross section for e+e
- -> pi+pi-, the pion form factor |F_pi|^2 and the dipion contribution to the muon magnetic moment anomaly, Delta a_mu^{pipi} = (478.5+-2.0_{stat}+-5.0_{syst}+-4.5_{th}) x 10^{-10} in the range 0.1 < M_{pipi}^2 < 0.85 GeV^2, where the theoretical error includes a SU(3) ChPT estimate of the uncertainty on photon radiation from the final pions. The discrepancy between the Standard Model evaluation of a_mu and the value measured by the Muon g-2 collaboration at BNL is confirmed.
