Two-photon width of the charmonium state χc2

The two-photon width of χ_c2(P23) state of charmonium has been measured using 14.4fb^-1 of e⁺e^- data taken at s=9.46 11.30GeV with the CLEO III detector. The γγ-fusion reaction studied is e⁺e^-→e⁺e^-γγ, γγ→χ_c2→γJ/ψ→γe⁺e^-(μ⁺μ^-). We measure Γ_γγ(χ_c2)B(χ_c2→γJ/ψ)B(J/ψ→e⁺e^-+μ⁺μ^-)=13.2±1.4(stat)±1.1(syst)eV, and obtain Γ_γγ(χ_c2)=559±57(stat)±48(syst)±36(br)eV. This result is in excellent agreement with the result of γγ-fusion measurement by Belle and is consistent with that of the p¯p→χ_c2→γγ measurement, when they are both reevaluated using the recent CLEO result for the radiative decay χ_c2→γJ/ψ.