Study of the γγ decays of the χ c2 (1 3 P 2 ) and χ c0 (1 3 P 0 ) charmonium resonances

We report the branching ratios of the {chi}{sub c2}(1{sup 3}P{sub 2}) and {chi}{sub c0}(1{sup 3}P{sub 0}) charmonium resonances to two photons using event samples collected by Fermilab experiment E835 in the reactions p(bar sign)p{yields}{chi}{sub c2}(1{sup 3}P{sub 2})[{chi}{sub c0}(1{sup 3}P{sub 0})]. Our result for the {chi}{sub c2} is B({chi}{sub c2}{yields}{gamma}{gamma})=(1.35{+-}0.25{+-}0.12)x10{sup -4}. We set a 95% upper limit for the {chi}{sub c0} branching ratio B({chi}{sub c0}{yields}{gamma}{gamma}) at 2.09x10{sup -4}. (c) 2000 The American Physical Society.