space, so the scalars near 1 GeV and the f$_{0}$ (1500) could also be investigated. η$_{c}$ → p ¯ pf$_{0}$ has a comparable the- oretical branching fraction, but the difficulty of produc- ing the η$_{c}$ makes this a less attractive channel. Finally, the χ$_{cJ}$ states are predicted to have much smaller p ¯ pf$_{0}$ branching fractions than J/ψ → p ¯ pf$_{0}$ , and accordingly are less attractive experimentally if this decay model is accurate. study, as well as to search for the f$_{0}$ (980) and a$_{0}$ (980) scalar states and the scalar glueball candidate f$_{0}$ (1500) in (higher-mass) charmonium decays, notably of the ψ $^{′}$. Charmonium decays to N ¯ Nω are especially interest- ing, since the ω plays a crucial role in meson-exchange models of the NN force, as the dominant origin of the short-ranged “hard core repulsion”, through t -channel ω exchange. Conceptual problems with this ω -exchange mechanism include 1) the very small NN separation im- plied by this mechanism ( R$_{NN}$ ≈ 1 /m$_{V}$ ≈ 0 . 3 fm), at which quark-gluon dynamics may be a more appropriate description of the interaction, and 2) the prediction of a corresponding short-ranged N ¯ N attraction and deeply bound N ¯ N states, which are not observed. (See for ex- ample Refs.[31–33], and references cited therein.) We have also estimated the effect of an f$_{0}$ (500) width on these results. Imposing a Breit-Wigner f$_{0}$ mass profile with Γ$_{f}$$_{0}$ = 0 . 5 GeV, truncated at 2 m$_{π}$ , decreases all the absolute theoretical Ψ → p ¯ pf$_{0}$ (500) branching fractions in Table II (col.3) by ≈ 10%. The relative theoretical branching fractions (col.2) are even less sensitive to the f$_{0}$ (500) width, and become 0 . 41 , 0 . 048 , 0 . 017 and 0 . 21. A light scalar f$_{0}$ meson would presumably decay strongly and perhaps dominantly to ππ , so decays of the type Ψ → p ¯ pππ are of special interest, notably J/ψ → p ¯ pππ (in view of our large theoretical B ( J/ψ → p ¯ pf$_{0}$ (500))). The charged case J/ψ → p ¯ pπ $^{+}$π − has been studied by Mark-I [27], DESY [30] and Mark-II [29]. Al- though no light scalar mesons have yet been identified in this decay, it is suggestive that J/ψ → p ¯ pπ $^{+}$π − is the largest known exclusive J/ψ → p ¯ pX mode, with a branching fraction of B ( J/ψ → p ¯ pπ $^{+}$π $^{−}$) = (6 . 0 ± 0 . 5) · 10 − $^{3}$. In addition to the p ¯ pf$_{0}$ intermediate state of interest here, this decay may also receive important contributions from NN $^{∗}$, N $^{∗}$N ∗ and ΔΔ, as well as other two-baryon and NNm states; this may complicate the comparison with experiment considerably. Ref.[29], which has the largest event sample, finds a large but not dominant ΔΔ contribution, B ( J/ψ → Δ ++ ¯ Δ $^{−−}$) = (1 . 10 ± 0 . 29) · 10 − $^{3}$, and gives a rather tight upper limit of ≈ 5% on the con- tributing subprocess J/ψ → p ¯ pρ $^{0}$; B ( J/ψ → p ¯ pρ $^{0}$) < 3 . 1 · 10 − 4 (90% c.l.). As Ref.[29] shows in their Fig.31 that the π $^{+}$π − invariant mass distribution from non-ΔΔ events is a broad sigma-like distribution, there may well be a large J/ψ → p ¯ pf$_{0}$ ( ∼ 500) → p ¯ pπ $^{+}$π − contribution to this decay, with a branching fraction comparable to the theoretical 3 . 4 · 10 − 3 predicted for g$_{NNf}$$_{0}$ = 10 (see Table II). It will be very interesting to investigate this possible light f$_{0}$ contribution in a future experimental Results from experimental studies of the decay J/ψ → p ¯ pω have been published by Mark-I [27], Mark-II [29] and most recently BES-II [5]. The PDG value of the J/ψ → p ¯ pω branching fraction, estimated from these results, is Charmonium decays to p ¯ pω final states (and N ¯ NV more generally) may allow independent estimates of these NNω and NNV couplings, again provided that they are dominated by the meson emission decay mechanism, or at least that this contribution to the decay amplitude can be isolated and quantified. In the following discussion we will consider the decay J/ψ → p ¯ pω as an example. There are two strong coupling constants in the NNω vertex, as summarized by Eq.(5), the overall strength g$_{NNω}$ of the Dirac ( γ$_{µ}$ ) coupling, and the relative strong magnetic Pauli coupling κ$_{NNω}$ (here abbreviated g$_{ω}$ and κ$_{ω}$ , with α$_{ω}$ = g 2 $_{ω}$/ 4 π ). Unfortunately the NNV cou- plings in the meson exchange models are not a priori well established experimentally, and are therefore usually fit- ted directly to NN scattering data. These NN scattering studies are thus fits to the data rather than predictions that test the assumed vector-meson-exchange scattering mechanism. These NN fits typically find g$_{ω}$ ≈ 10-15 for the Dirac NNω coupling, whereas the NNω Pauli cou- pling has remained poorly determined; examples of NNω parameter sets from the NN scattering literature in- clude ( g$_{ω}$, κ$_{ω}$ ) = (12 . 2 , − 0 . 12) (Paris), (12 . 5 , +0 . 66) (Ni- jmegen), and (15 . 9 , 0) (CD-Bonn) (these are cited in Ref.[34]). Independent estimates of the NNω coupling from experiment have been reported by Sato and Lee [35] (from pion photoproduction) and by Mergell, Meissner and Drechsel [36] (from nucleon EM form factors). Sato et al. assumed κ$_{ω}$ = 0, and quoted the range g$_{ω}$ = 7-10 . 5 for experimentally favored values of the Dirac coupling. Mergell et al. found a small κ$_{ω}$ but a much larger Dirac coupling, ( g$_{ω}$, κ$_{ω}$ ) = (20 . 86 ± 0 . 25 , − 0 . 16 ± 0 . 01). The- oretical calculations include a QCD sum rule result of Zhu [37], who finds ( g$_{ω}$, κ$_{ω}$ ) = (18 ± 8 , 0 . 8 ± 0 . 4), and a recent $^{3}$P$_{0}$ quark model calculation of NNm couplings [34] which found the analytic result κ$_{ω}$ = − 3 / 2. TABLE II: Theoretical (meson emission model) branching fractions for light scalar meson production. The numeri- cal columns are 1) The ratio B (Ψ → p ¯ pf$_{0}$ (500)) /B ( J/ψ → p ¯ pf$_{0}$ (500)); 2) 10 3 · B (Ψ → p ¯ pf$_{0}$ (500)) for g$_{NNf}$$_{0}$ = 10; 3) 10 3 · B $^{expt.}$(Ψ → p ¯ pπ $^{+}$π $^{−}$), for comparison with 2) . (See text.) F. Decays to NNω and NNV 7 Ψ B thy. p ¯ $_{pf$_{0}$}$/B$_{0}$ 10 3 · B thy. ( g =10) p ¯ pf$_{0}$ 10 3 · B expt. p ¯ pπ $^{+}$π − η c 0 . 40 1 . 4 < 12 (90% c.l.) J/ψ ≡ 1 3 . 4 6 . 0 ± 0 . 5 χ$_{0}$ 0.045 0 . 15 2 . 1 ± 0 . 7 χ$_{1}$ 0 . 016 0 . 054 0 . 50 ± 0 . 19 ψ ′ 0 . 21 0 . 72 0 . 60 ± 0 . 04