Charmonium spectroscopy from inclusive ψ’ andJ/ψradiative decays

Results from a detailed study using the Crystal Ball detector at the SLAC e⁺{e}^{{{-}}}storage ring SPEAR of the inclusive photon spectra from 1.8×{10}⁶ψ' and 2.2×{10}⁶J/ψ decays are presented. Radiative transitions from the ψ' to the{{χ}}₂$,1,0 states are observed with photon energies of 126.0±{}0.2±{}4, 169.6±{}0.3±{}4, and 258.4±{}0.4±{}4 MeV and branching ratios B({ψ}'{→}{γ}χ₂,1,0) =(8.0±{}0.5±{}0.7)%, (9.0±{}0.5±{}0.7)%, and (9.9±{}0.5±{}0.8)%, respectively. Values for the natural linewidths of the {χ} states are obtained: {Γ}(χ₂,1,0)=0.8--4.9, <3.8, and 13--21 MeV, respectively (90% C.L.). Improved values are found for the branching ratios B({ψ}'{→}{γ}ηc) =(0.28±{}0.06)% and B(J/{ψ}{→}{γ}ηc)=(1.27±{}0.36)%, and for the natural width {Γ}(ηc)=11.5±{}4.5 MeV.