Possible open-charmed pentaquark molecule – the bound state – in the Bethe–Salpeter formalism Chao Wang, Liang-Liang Liu, Xian-Wei Kang, Xin-Heng Guo and Rui-Wu Wang Eur. Phys. J. C, 78 5 (2018) 407 Published online: 23 May 2018 DOI: 10.1140/epjc/s10052-018-5874-1