1212.5325 (Jian-Rong Zhang)

$S$-wave $D^{(*)}N$ molecular states: $Σ_{c}(2800)$ and
$Λ_{c}(2940)^{+}$?    [PDF]

Jian-Rong Zhang

Theoretically, some works have proposed the hadronic resonances $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ to be $S$-wave $DN$ and $D^{*}N$ molecular candidates, respectively. In the framework of QCD sum rules, we investigate that whether $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ could be explained as the $S$-wave $DN$ state with $J^{P}=(1/2)^{-}$ and the $S$-wave $D^{*}N$ state with $J^{P}=(3/2)^{-}$, respectively. Technically, contributions of operators up to dimension 12 are included in the operator product expansion (OPE). The final results are $3.52\pm0.36 GeV$ and $3.59\pm0.41 GeV$ for the $S$-wave $DN$ state of $J^{P}=(1/2)^{-}$ and the $S$-wave $D^{*}N$ state of $J^{P}=(3/2)^{-}$, respectively. They are somewhat bigger than the experimental data of $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$, respectively. These results do not support the statements that $\Sigma_{c}(2800)$ could be the $S$-wave $DN$ molecule with $J^{P}=(1/2)^{-}$ and $\Lambda_{c}(2940)^{+}$ be the $S$-wave $D^{*}N$ molecule with $J^{P}=(3/2)^{-}$, respectively. As byproducts, masses for their bottom partners are predicted to be $6.97\pm0.55 GeV$ for the $S$-wave $BN$ state of $J^{P}=(1/2)^{-}$ and $6.98\pm0.56 GeV$ for the $S$-wave $B^{*}N$ state of $J^{P}=(3/2)^{-}$.

View original: http://arxiv.org/abs/1212.5325