Speaker
Description
Physics program of the experiments with the CMD-3 includes precise measurement of the cross-sections of the e+e− → hadrons processes. Such measurements are necessary for the calculation of the hadronic contribution to the anomalous magnetic moment of the muon (α=(g−2)/2). Value of α is one of the great instrument for the Standard Model test. Among hadronic channels the process e+e− → π+π− is very important because it gives the main contribution to the value of hadronic part of α (~72%) in the low energy region (S < 2 GeV2).
Radiative corrections to the e+e− → π+π− cross-section are calculated under the hypothesis of point-like pions. In this work we study of the e+e− → π+π−γ process with photon radiation from the final state and test of the hypothesis about point-like pions used in the MCGPJ generator. In order to increase a part of events with FSR we study this process in the energy region left from the ρ-meson peak. The analysis of the process e+e− → π+π−γ was carried out in the energy region 660÷785 MeV and based on the integrated luminosity about 8.4 pb-1. The comparison of the experimental data for photon energy spectrum with the simulation results are in agreement with the hypothesis of point-like pions.
