Study of the reactions

Abstract

We study the processes e^{+}e^{-}→π^{+}π^{-}π^{0}π^{0}π^{0}γ and π^{+}π^{-}π^{0}π^{0}ηγ in which an energetic photon is radiated from the initial state. The data are collected with the BABAR detector at SLAC. About 14 000 and 4700 events, respectively, are selected from a data sample corresponding to an integrated luminosity of 469 fb^{-1}. The invariant mass of the hadronic final state defines the effective e^{+}e^{-} center-of-mass energy. From the mass spectra, the first precise measurement of the e^{+}e^{-}→π^{+}π^{-}π^{0}π^{0}π^{0} cross section and the first measurement ever of the e^{+}e^{-}→π^{+}π^{-}π^{0}π^{0}η cross section are performed. The center-of-mass energies range from threshold to 4.35 GeV. The systematic uncertainty is typically between 10% and 13%. The contributions from ωπ^{0}π^{0}, ηπ^{+}π^{-}, and other intermediate states are presented. We observe the J/ψ and ψ(2S) in most of these final states and measure the corresponding branching fractions, many of them for the first time.