Eur. Phys. J. C (2018) 78: 407
https://doi.org/10.1140/epjc/s10052-018-5874-1

Regular Article - Theoretical Physics

Possible open-charmed pentaquark molecule – the bound state – in the Bethe–Salpeter formalism

¹ Center for Ecological and Environmental Sciences, Key Laboratory for Space Bioscience and Biotechnology, Northwestern Polytechnical University, Xi’an, 710072, China
² College of Physics and Information Engineering, Shanxi Normal University, Linfen, 041004, China
³ College of Nuclear Science and Technology, Beijing Normal University, Beijing, 100875, China
⁴ Institute of Physics, Academia Sinica, Taipei, 115, Taiwan

^* e-mail: xhguo@bnu.edu.cn
^** e-mail: wangrw@nwpu.edu.cn

Received: 9 April 2018
Accepted: 4 May 2018
Published online: 23 May 2018

Abstract

We study the S-wave bound state in the Bethe–Salpeter formalism in the ladder and instantaneous approximations. With the kernel generated by the hadronic effective Lagrangian, two open-charmed bound states, which quantum numbers are ,  and , , respectively, are predicted as new candidates of hadronic pentaquark molecules in our formalism. If existing, they could contribute to the broad 3188 MeV structure near the five new narrow states observed recently by the LHCb Collaboration.