Measurement of relative probability of decay φ → ηγ in channel η → π+π-π0

Using the VEPP-2M facility with counter electron-positron beams one measured the relative probability of φ-meson B(φ → ηγ) decay in η → π+π-π0 channel. One conducted experiments using a spherical neutral detector (SND). One studied in detail the procedure to select events and their kinematic reconstruction. Paper shows the results of resonance curve fitting for every scanning. On the basis of the derived experimental data one determined the relative probability of B(φ → ηγ) decay equal to (1.25 ± 0.030 ± 0.59)% in η → π+π-π0 decay channel. The derived result conforms with the table value and with measurement of this probability using SND detector in other channels of η-meson decay