Partial wave analyses of J/ψ→γπ+π− and γπ0<

Abstract

Partial wave analyses of J/ψ → γπ

Comprehensive study of the radiative decays ofJ/ψandψ(2S)to pseudoscalar meson pairs, and search for glueballs

“…BES II also observes kaon yields in this general mass region, but does not quote any numerical results [19].…”

“…We therefore assume five different values of the width, Γ = 100, 125, 150, 175, and 200 MeV, and fit the π + π − spectrum for the best value of the mass corresponding to each assumed value of the width. The corresponding best fit values are found to be respectively: M (MeV) = 1452(13), 1445(15), 1439(17), 1432 (19), and 1424 (23). These results indicate that the observed narrow "bump" can be only assigned to f 0 (1500) (for which many recent measurements report M ≈ 1470 MeV [26]), and not to f 0 (1370).…”

“….0(9)(58), and B 1 × B 2 (ππ) × 10 5 = 131.4(11)(159), obtained by BES II [19] for directly produced J/ψ. We note that the BES spectra have much larger backgrounds which may account for the substantial difference from our results.…”

“…Radiative decays of J/ψ have been studied by Crystal Ball [14], Mark III [15,16], DM2 [17], and BES [18][19][20]. Among the latest of these are BES measurements of J/ψ → γ(π + π − , π 0 π 0 ) [18] and J/ψ → γ( [20] with 58 million directly produced J/ψ in e + e − → J/ψ.…”

Vector meson-vector meson interaction and dynamically generated resonances

“…Our calculated branching ratio for the ηη channel is in agreement with their average, while the ratio for the ππ channel is much smaller. However, we notice that the above PDG Γ(ππ)/Γ(KK) ratio is taken from the BES data on J/ψ → γπ + π − [17], which comes from a partial wave analysis that includes seven resonances. On the other hand, the BES data on J/ψ → ωK + K − [18] give an upper limit Γ(ππ)/Γ(KK) < 11% at the 95% confidence level.…”