Baryonium X(1835)
  The relativistic six-quark equations including the u, d quarks and antiquarks are found. The nonstrange baryonia B/bar B are contructed without the mixing of the quarks and antiquarks. The relativistic six-quark amplitudes of the baryonia are calculed. The poles of these amplitudes determine the masses of baryonia. 16 masses of baryonia are predicted. 
S.M. Gerasyuta and E.E. Matskevich
hep-ph