Speaker
Sergey Tolmachev
(assistant)
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 (αμhad) to the anomalous magnetic moment of the muon (αμ=(g−2)/2). Value of αμ 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 αμhad (~72%) in the low energy region (S < 2 GeV2).
Radiative corrections to the e+e− → π+π− process are calculated under the assumption 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 experimental data for photon energy spectrum with the simulation results are in agreement. with the assumption of point-like pions.
Primary author
Sergey Tolmachev
(assistant)
