AbstractThe process $$e^+e^-\rightarrow \eta \pi ^0\gamma $$
e
+
e
-
→
η
π
0
γ
is studied in the center-of-mass energy range 1.05–2.00 GeV using data with an integrated luminosity of 94.5 $$\hbox {pb}^{-1}$$
pb
-
1
collected by the SND detector at the VEPP-2000 $$e^{+}e^{-}$$
e
+
e
-
collider. The $$e^+e^-\rightarrow \eta \pi ^0\gamma $$
e
+
e
-
→
η
π
0
γ
cross section is measured for the first time. It is shown that the dominant mechanism of this reaction is the transition through the $$\omega \eta $$
ω
η
intermediate state. The measured cross section of the subprocess $$e^+e^-\rightarrow \omega \eta \rightarrow \eta \pi ^0\gamma $$
e
+
e
-
→
ω
η
→
η
π
0
γ
is consistent with previous measurements in the $$e^+e^-\rightarrow \pi ^+\pi ^-\pi ^0\eta $$
e
+
e
-
→
π
+
π
-
π
0
η
mode. It is found, with a significance of $$5.6\sigma $$
5.6
σ
, that the process $$e^+e^-\rightarrow \eta \pi ^0\gamma $$
e
+
e
-
→
η
π
0
γ
is not completely described by hadronic vector-pseudoscalar intermediate states. The cross section of this missing contribution, which can originate from radiation processes, e. g. $$e^+e^-\rightarrow a_{0}(1450)\gamma $$
e
+
e
-
→
a
0
(
1450
)
γ
, is measured. It is found to be 15–20 pb in the wide energy range from 1.3 to 1.9 GeV.
Study of the e+e−→ KS KLπ0 process up to 2 GeV with the CMD-3 detector at the VEPP-2000 collider