PNNL

Abstract

Using the data for 24.5 × 106 ?(2S) produced in e+e- annihilations at vs = 3686 MeV at the CESR-c e+e- collider and 8.6 × 106 J/? produced in the decay ?(2S) ? p+p-J/?, thebranching fractions for ?(2S) and J/? decays to pairs of pseudoscalar mesons, p+p-, K+K-, and KSKL, have been measured using the CLEO-c detector. We obtain branching fractions B(?(2S) ?p+p-) = (7.6 ± 2.5 ± 0.6) × 10-6, B(?(2S) ? K+K-) = (74.8 ± 2.3 ± 3.9) × 10-6, B(?(2S) ?KSKL) = (52.8 ± 2.5 ± 3.4) × 10-6, and B(J/? ? p+p-) = (1.47 ± 0.13 ± 0.13) × 10-4, B(J/? ?K+K-) = (2.86 ± 0.09 ± 0.19) × 10-4, B(J/? ? KSKL) = (2.62 ± 0.15 ± 0.14) × 10-4, wherethe first errors are statistical and the second errors are systematic. The phase differences between the amplitudes for electromagnetic and strong decays of ?(2S) and J/? to 0-+ pseudoscalar pairs are determined by a Monte Carlo method to be d(?(2S)PP = (110.5+16.0)? and d(J/?)PP = -9.5 (73.5+5.0)?. The difference between the two is ?d = d(?(2S))PP - d(J/?)PP = (37.0+16.5)?.