A mixing coupling scheme for spectra of singly heavy baryons with spin-1 diquarks in P-waves Duojie Jia, Ji-Hai Pan and Cheng-Qun Pang Eur. Phys. J. C, 81 5 (2021) 434 Published online: 20 May 2021 DOI: 10.1140/epjc/s10052-021-09205-6