The molecular systems composed of the charmed mesons in the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$H\bar{S}+h.c.$\end{document} doublet

We study the possible heavy molecular states composed of a pair of charm mesons in the H and S doublets. Since the P-wave charm-strange mesons Ds0(2317) and Ds1(2460) are extremely narrow, the future experimental observation of the possible heavy molecular states composed of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$D_{s}/D_{s}^{\ast}$\end{document} and Ds0(2317)/Ds1(2460) may be feasible if they really exist. Especially the possible JPC=1−− states may be searched for via the initial state radiation technique.