Study on NbarN} Swave Elastic Cross Section and Possible Bound States Within a Consti.pdf

Study on NN S-wave Elastic Cross Section and Possible Bound States Within a Constituent Quark Model Hourong Pang Department of Physics, Southeast University, Nanjing, 210094, P.R.China 7 Jialun Ping 0 0 Department of Physics, Nanjing Normal University, Nanjing, 210097, P.R.China 2 c e Fan Wang D Joint Center of Particle, Nuclear Physics and Cosmology, 8 2 and Department of physics, Nanjing University, Nanjing, 210093, P.R.China ] h Abstract t - l In the framework of a chiral constituent quark model, considering the contributions of π anni- c u n hilation and one-gluon annihilation, the proton-antiproton S-wave elastic scattering cross section [ experimental data can be reproduced by adjusting properly one-gluon annihilation coupling con- 1 v stant. Meanwhile, using the fixed model parameter, we do a dynamical calculation for all possible 6 7 3 S-wave nucleon-antinucleon states, the results show that, there is no S-wave bound state as indi- 4 . cated by a strong enhancement at threshold of pp¯ in J/ and B decays. 2 1 7 0 PACS numbers: 12.39.Jh, 14.20.Pt, 13.75.Cs : v i X r a 1 I. INTRODUCTION Theoretical studies of baryonantibaryon bound states date back to the proposal of Fermi and Yang [1] to make the pion with a nucleonantinucleon pair. The traditional NN inter action studies, such as boundary condition model [2], optical model [3] and coupledchannel