s-wave nucleon-antinucleon interaction in the constituent quark model

A calculation of the quark rearrangements process NN¯to three mesons is presented in the constituent quark model. Using quark cluster wave functions we determine the absolute magnitude of the real and imaginary NN¯optical potential from three-meson annihilation. In the local approximation the range of the s-wave potential is of the size of the baryon wave function and the potential has a strength of ≈1 GeV. When the long range tensor meson exchange potential is added to the short range quark rearrangement potential we reproduce the NN¯s-wave elastic and inelastic cross sections quite well. With the same potential s-wave branching ratios into various meson channels are calculated. They agree moderately well with experiment.