content_image/400880.jpg content_image/400883.jpg content_image/400879.jpg content_image/400884.jpg content_image/400881.jpg content_image/400882.jpg
B ( J/ψ → p ¯ pω ) = (1 . 10 ± 0 . 15) · 10 − $^{3}$, which combined with the PDG J/ψ total width gives an experimental partial width of 

The fact that this is approximately equal to the p ¯ pπ 0 partial width (19) despite the much smaller phase space suggests a robust NNω coupling. 

On evaluating this theoretical decay rate by in- tegrating Eq.(15) numerically with physical masses, both NNω couplings free, and (as used previously) g$_{J/ψp}$$_{¯}$ p = 1 . 62 · 10 − $^{3}$, we find 

<img src='content_image/400880.jpg'>

The single number Γ( J/ψ → p ¯ pω ) alone does not suf- fice to determine the NNω strong couplings since there are two free parameters, g$_{ω}$ and κ$_{ω}$ . If we set κ$_{ω}$ = 0, following CD-Bonn [15] and the Sato-Lee photoproduc- tion study [35], the measured partial width (31) and the theoretical decay rate (32) imply g$_{ω}$ = 23 ± 3 (provided that meson emission dominates this decay). This g$_{ω}$ is rather larger than these references prefer for g$_{ω}$ ; it is con- sistent however with the EM form factor fit of Mergell et al. [36] and the range 18 ± 8 reported by Zhu [37] from QCD sum rules. If we instead assume the $^{3}$P$_{0}$ quark model value κ$_{ω}$ = − 3 / 2 for the Pauli term [34], we find g$_{ω}$ = 14 . 6 ± 2 . 0, which is consistent with the values quoted by NN scattering studies, and is somewhat larger than the photoproduction value. 

It is possible to estimate the two parameters g$_{ω}$ and κ$_{ω}$ independently through a more detailed comparison be- 0 

<img src='content_image/400883.jpg'>

<img src='content_image/400879.jpg'>

tween J/ψ → p ¯ pω data and the theoretical DP event den- sity, Eq.(15). This theoretical event density is strongly dependent on the Pauli coefficient κ$_{ω}$ ; with κ$_{ω}$ = 0 the event density at lower M$_{p}$$_{¯}$ p is strongly suppressed (see Fig.4). 

In contrast, for moderately large | κ$_{ω}$ | , such as the quark model value κ$_{ω}$ = − 3 / 2, the theoretical DP event density is closer to uniform. This is illustrated in Fig.5, which shows this event density along the diagonal M 2 pω = M 2 ¯ pω (relative to the maximum value on diago- nal) for various κ$_{ω}$ ≤ 0. If the meson emission model does give a good description of this decay, evidently it may be possible to determine κ$_{ω}$ by comparing the J/ψ → p ¯ pω DP event density on diagonal to the prediction in Fig.5. 

<img src='content_image/400884.jpg'>

Other decays to p ¯ pV final states that are closely related to J/ψ → p ¯ pω include J/ψ → p ¯ pρ 0 and J/ψ → p ¯ pφ . In the m eson emission model these are both described by the d ecay formula (15), albeit with different vector meson m asses and NNV couplings. Given the rounded PDG ma sses m$_{ρ}$ 0 = 0 . 7755 GeV and m$_{φ}$ = 1 . 0195 GeV, we pred ict the numerical decay widths 

<img src='content_image/400881.jpg'>

and 

<img src='content_image/400882.jpg'>

The ρ case is especially interesting due to the range of values reported for κ$_{ρ}$ , as discussed by Brown and Mach- leidt [38]. Although vector dominance predicts κ$_{ρ}$ = 3 . 7 “weak ρ ”, and some data has been interpreted as sup- porting this, fits to ππ → N ¯ N and S-D mixing in NN 

## G. Other Ψ → p ¯ pV decays 

