Analysis of the X(1835) and related baryonium states with Bethe-Salpeter equation

In this article, we study the mass spectrum of the baryon-antibaryon bound states p `(p)] \bar{{p}} , S \Sigma `(S)] \bar{{\Sigma}} , X \Xi `(X)] \bar{{\Xi}} , L \Lambda `(L)] \bar{{\Lambda}} , p `(N)] \bar{{N}}(1440) , S \Sigma `(S)] \bar{{\Sigma}}(1660) , X \Xi `(X)]<sup>￠</sup> \bar{{\Xi}}^{{\prime}}_{} and L \Lambda `(L)] \bar{{\Lambda}}(1600) with the Bethe-Salpeter equation. The numerical results indicate that the p `(p)] \bar{{p}} , S \Sigma `(S)] \bar{{\Sigma}} , X \Xi `(X)] \bar{{\Xi}} , p `(N)] \bar{{N}}(1440) , S \Sigma `(S)] \bar{{\Sigma}}(1660) , X \Xi `(X)]^￠ \bar{{\Xi}}^{{\prime}}_{} bound states maybe exist, and the new resonances X(1835) and X(2370) can be tentatively identified as the p `(p)] \bar{{p}} and p `(N)] \bar{{N}}(1440) (or N(1400)`(p)] \bar{{p}} bound states, respectively, with some gluon constituents, and the new resonance X(2120) may be a pseudoscalar glueball. On the other hand, the Regge trajectory favors identifying the X(1835) , X(2120) and X(2370) as the excited h^￠ \eta^{{\prime}}_{}(958) mesons with the radial quantum numbers n = 3 , 4 and 5, respectively.