Study of $e^{+}{e}^{-}\to \omega {\chi }_{cJ}$ at center-of-mass energies from 4.21 to 4.42 GeV

Based on data samples collected with the BESIII detector at the BEPCII collider at 9 center-of-mass energies from 4.21 to 4.42 GeV, we search for the production of $e^{+}{e}^{-}\to \omega {\chi }_{cJ}$ ($J$=0, 1, 2). The process $e^+e^-\to \omega\chi_{c0}$isobservedforthefirsttime,andtheBorncrosssectionsat$\sqrt{s}$=4.23and4.26GeVaremeasuredtobe$(55.4\pm 6.0\pm 5.9)$and$(23.7\pm 5.3\pm 3.5)$ pb, respectively, where the first uncertainties are statistical and the second are systematic. The $\omega {\chi }_{c0}$ signals at the other 7 energies and $e^{+}{e}^{-}\to \omega {\chi }_{c1}$ and $\omega {\chi }_{c2}$ signals are not significant, and the upper limits on the cross sections are determined. By examining the $\omega {\chi }_{c0}$ cross section as a function of center-of-mass energy, we find that it is inconsistent with the line shape of the $Y(4260)$ observed in $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}J\mathrm{/}\psi$. Assuming the $\omega {\chi }_{c0}$ signals come from a single resonance, we extract mass and width of the resonance to be $(4230\pm 8\pm 6)$ MeV/$c^2$ and $(38\pm 12\pm 2)$ MeV, respectively, and the statistical significance is more than $9\sigma$.