Scanning of the e+e- to pi+pi- cross--section below 1 GeV by radiative   events with untagged photon
  We discuss an inclusive approach to the measurement of the e+e- --> pi+ pi- cross--section by the radiative return method without photon tagging. The essential part of this approach is the choice of rules for event selection which provide rejection of events with 3 (or more) pions and decrease the final--state radiation background. The radiative corrections to the initial--state radiation process are computed for DAPhNE conditions, using the quasi--real electron approximation for both, the cross--section and the underlying kinematics. The two cases of restricted and unrestricted pion phase space are considered. Some numerical calculations illustrate our analytical results. 
V.A. Khoze, M.I. Konchatnij, N.P. Merenkov, G. Pancheri, L. Trentadue,   O.N. Shekhovtzova