Nucleon-antinucleon Interaction from the Modified Skyrme Model

We calculate the static nucleon-antinucleon interaction potential from the modified Skyrme model with additional $B^{\mu}B_{\mu}$ term using the product ansatz. The static properties of single baryon are improved in the modified Skyrme model. State mixing is taken into account by perturbation theory, which substantially increases the strength of the central attraction. We obtain a long and mid range potential which is in qualitative agreement with some phenomenological potentials.Comment: 21 pages, 7 figur

X(1835)X(1835) and the New Resonances X(2120)X(2120) and X(2370)X(2370) Observed by the BES Collaboration

We calculate the decay widths of both the second and the third radial excitations of $\eta$ and $\eta'$ within the framework of $^3P_0$ model. After comparing the theoretical decay widths and decay patterns with the available experimental data of $\eta(1760)$, $X(1835)$, $X(2120)$ and $X(2370)$, we find that the interpretation of $\eta(1760)$ and $X(1835)$ as the second radial excitation of $\eta$ and $\eta'$ crucially depends on the measured mass and width of $\eta(1760)$, which is still controversial experimentally. We suggest that there may be sizable $p\bar{p}$ content in $X(1835)$. $X(2120)$ and $X(2370)$ can not be understood as the third radial excitations of $\eta$ and $\eta'$, $X(2370)$ probably is a mixture of $\eta'(4{^1}{S}{_0})$ and glueball.Comment: 20 pages, 6 figure