Productions of X(1835) as baryonium with sizable gluon content

Abstract

The X(1835) has been treated as a baryonium with sizable gluon content, and to be almost flavor singlet. This picture allows us to rationally understand X(1835) production in $J/ψ$ radiative decays, and its large couplings with $p\bar{p}$, $η^{\prime}ππ$. The processes $Υ(1S)\to γX(1835)$ and $J/ψ\to ωX(1835)$ have been examined. It has been found that $Br(Υ(1S)\toγX(1835))Br(X(1835)\to p\bar{p})<6.45\times10^{-7}$, which is compatible with CLEO&#39;s recently experimental result (Phys.Rev.$\mathbf{D73}$ (2006) 032001;hep-ex/0510015). The branching fractions of $Br(J/ψ\toωX(1835))$, $Br(J/ψ\toρX(1835))$ with $X(1835)\to p\bar{p}$ and $X(1835)\toη^{\prime}π^{+}π^{-}$ have been estimated by the quark-pair creation model. We show that they are heavily suppressed, so the signal of X(1835) is very difficult, if not impossible, to be observed in these processes. The experimental checks for these estimations are expected. The existence of the baryonium nonet is conjectured, and a model independent derivation of their production branching fractions is presented.