10 B.S.Zou regarding this research, and Shu-Min Li and Xiao-Yan Shen in particular for contributing the BES data used in preparing Fig.3. We also gratefully ac- knowledge the support of the Department of Physics and Astronomy of the University of Tennessee, the Physics Division of Oak Ridge National Laboratory, and the De- partment of Physics, the College of Arts and Sciences, and the Office of Research at Florida State University. This research was sponsored in part by the Office of Nu- clear Physics, U.S. Department of Energy. one should include other significant decay mechanisms, as they become apparent through high-statistics studies of experimental Dalitz plots. These additional mecha- nisms might include intermediate meson resonances m ′ that couple strongly to N ¯ N , as in Ψ → m $^{′}$m → p ¯ pm ; if the m ′ resonances lie in the physical region, they will give rise to characteristic m ′ resonance bands in M$_{p}$$_{¯}$ p that could be identified and incorporated in a more complete decay model. We are happy to acknowledge useful communications with R.Mitchell, K.Seth, M.Shepherd, E.S.Swanson and V. ACKNOWLEDGMENTS [1] M. Ablikim et al. [BES Collaboration], Phys. Rev. D 80 , 052004 (2009) [arXiv:0905.1562 [hep-ex]]. [2] M. Ablikim et al. [BES Collaboration], Phys. Rev. D 71 , 072006 (2005) [arXiv:hep-ex/0503030]. [3] M. Ablikim et al. [BES Collaboration], Phys. Rev. D 74 , 012004 (2006) [arXiv:hep-ex/0605031]. [4] M. Ablikim et al. [BES Collaboration], arXiv:0902.3501 [hep-ex]. [5] M. Ablikim et al. [BES Collaboration], Eur. Phys. J. C 53 , 15 (2008) [arXiv:0710.5369 [hep-ex]]. [6] J. Z. Bai et al. [BES Collaboration], Phys. Rev. Lett. 91 , 022001 (2003) [arXiv:hep-ex/0303006]. [7] M. Ablikim et al. [BES Collaboration], Phys. Rev. Lett. 95 , 262001 (2005) [arXiv:hep-ex/0508025]. [8] Y.Huang, “Confirmation of proton-antiproton mass threshold enhancement structure and X(1835) at BES- III” (presentation at HADRON 2009). [9] A. Lundborg, T. Barnes and U. Wiedner, Phys. Rev. D 73 , 096003 (2006) [arXiv:hep-ph/0507166]. [10] Technical Progress Report for: ¯ PANDA, Strong Interac- tion Studies with Antiprotons (Feb. 2005). [11] R. A. Briere et al. [CLEO Collaboration], Phys. Rev. Lett. 95 , 062001 (2005) [arXiv:hep-ex/0505101]. [12] J. Z. Bai et al. [BES Collaboration], Phys. Rev. D 67 , 052002 (2003) [arXiv:hep-ex/0209080]. [13] S. B. Athar et al. [CLEO Collaboration], arXiv:hep-ex/0611032. [14] R. Machleidt, K. Holinde and C. Elster, Phys. Rept. 149 , 1 (1987). [15] R. Machleidt, Phys. Rev. C 63 , 024001 (2001) [arXiv:nucl-th/0006014]. [16] M. M. Nagels, T. A. Rijken and J. J. de Swart, Phys. Rev. D 15 , 2547 (1977). [17] M. M. Nagels, T. A. Rijken and J. J. de Swart, Phys. Rev. D 20 , 1633 (1979). [18] V. G. J. Stoks, R. A. M. Klomp, C. P. F. Terheggen and J. J. de Swart, Phys. Rev. C 49 , 2950 (1994) [arXiv:nucl-th/9406039]. [19] W. N. Cottingham, M. Lacombe, B. Loiseau, J. M. Richard and R. Vinh Mau, Phys. Rev. D 8 , [39] Shi-Lin Zhu, Phys. Rev. C 59 , 435 (1999) [arXiv:nucl-th/9809032]. [38] G. E. Brown and R. Machleidt, Phys. Rev. C 50 , 1731 (1994). [37] Shi-Lin Zhu, Phys. Rev. C 59 , 3455 (1999) [arXiv:nucl-th/9810031]. [36] P. Mergell, U. G. Meissner and D. Drechsel, Nucl. Phys. A 596 , 367 (1996) [arXiv:hep-ph/9506375]. [35] T. Sato and T. S. H. Lee, Phys. Rev. C 54 , 2660 (1996) [arXiv:nucl-th/9606009]. [34] C. Downum, T. Barnes, J. R. Stone and E. S. Swanson, Phys. Lett. B 638 , 455 (2006) [arXiv:nucl-th/0603020]. [33] T. Barnes, S. Capstick, M. D. Kovarik and E. S. Swanson, Phys. Rev. C 48 , 539 (1993) [arXiv:nucl-th/9302007]. [32] K. Maltman and N. Isgur, Phys. Rev. D 29 , 952 (1984). [31] K. Maltman and N. Isgur, Phys. Rev. Lett. 50 , 1827 (1983). [30] H. J. Besch et al. , Z. Phys. C 8 , 1 (1981). [29] M. W. Eaton et al. , Phys. Rev. D 29 , 804 (1984). [28] R. Brandelik et al. [DASP Collaboration], Z. Phys. C 1 , 233 (1979). [27] I. Peruzzi et al. , Phys. Rev. D 17 , 2901 (1978). [26] C. Amsler et al. (Particle Data Group), Phys. Lett. B 667 , 1 (2008), and 2009 partial update for the 2010 edition. [25] T. Barnes, X. Li and W. Roberts, Phys. Rev. D 77 , 056001 (2008) [arXiv:0709.4491 [hep-ph]]. [24] T. Barnes and X. Li, Phys. Rev. D 75 , 054018 (2007) [arXiv:hep-ph/0611340]. [23] S. Capstick and W. Roberts, Phys. Rev. D 58 , 074011 (1998) [arXiv:nucl-th/9804070]. [22] S. Capstick and N. Isgur, Phys. Rev. D 34 , 2809 (1986). [20] M. Lacombe, B. Loiseau, J. M. Richard, R. Vinh Mau, J. Conte, P. Pires and R. de Tourreil, Phys. Rev. C 21 , 861 (1980). [21] C. Downum, D. Phil., “ Low Energy Nucleon-Nucleon In- teractions from the Quark Model with Applications ”, Ox- ford University, 2009 (unpublished). 800 (1973).