Study Of The Process E(+)E(-) -> Eta Pi(0)Gamma In The Cossision-Energy Range Of Root S=1.05-2.00 Gev

The process e(+)e(-) -> eta pi(0)gamma is studied in the range of center-of-mass (c.m.) collision energies between 1.05 and 2.00 GeV on the basis of data corresponding to an integrated luminosity of 94.5 pb(-1) that were accumulated in an experiment with the SND detector at the VEPP-2000 e(+)e(-) collider. The cross section for this process was measured for the first time and was found to receive a dominant contribution from the mechanism of a transition through an omega eta intermediate state. The cross section measured for the process e(+)e(-) -> omega eta -> eta pi(0)gamma agrees with the results of earlier measurements in the channel e(+)e(-) -> pi(+)pi(-) pi(0)eta. At a level of 5.7 standard deviations (5.7 sigma), it is established that the process e(+)e(-) -> eta pi(0)gamma is not fully described by hadronic intermediate states of the V P type. The cross section was measured for this missing contribution, which may be generated by radiative processes-for example, e(+)e(-) -> a(0)(1450)gamma. It ranges from 15 to 20 pb over a broad energy interval extending from 1.3 to 1.9 GeV.