Origin of the black hole spin in lower-mass-gap black hole-neutron star binaries Ying Qin, Zhen-Han-Tao Wang, Georges Meynet, Rui-Chong Hu, Chengjie Fu, Xin-Wen Shu, Zi-Yuan Wang, Shuang-Xi Yi, Qing-Wen Tang, Han-Feng Song and En-Wei Liang A&A, 691 (2024) L19 Published online: 21 November 2024 DOI: 10.1051/0004-6361/202452335