χc2 formation in two-photon collisions at LEP

Two-photon formation of the charmonium resonance $\chi_{{\rm c}2}$ has been studied with the L3 detector at LEP. The $\chi_{{\rm c}2}$ is identified through its decay $\chi_{{\rm c}2} \rightarrow \gamma {\rm J}$, with a subsequent decay ${\rm J} \rightarrow {\mathrm{e^+ e^-}}$ or ${\rm J} \rightarrow {\mathrm{\mu^+ \mu^-}}$. With an integrated luminosity of 140 pb$^{-1}$ at $\sqrt{s} \simeq$ 91~\textrm{Ge\kern -0.1em V} and 52 pb$^{-1}$ at $\sqrt{s} \simeq$ {Ge\kern -0.1em V}, we measure the two-photon width of the $\chi_{{\rm c}2}$ to be \begin{center} $\Gamma_{\gamma\gamma}(\chi_{{\rm c}2})=1.02 \pm 0.40 \mbox{$\;$(stat.)} \pm 0.15 \mbox{$\;$(sys.)} \pm 0.09(\rm{BR.}) {\mathrm{\ ke\kern -0.1em V}}$.