Can the one-zone hadronuclear model explain the hard-TeV spectrum of BL Lac objects? Wei-Jian Li, Rui Xue, Guang-Bo Long, Ze-Rui Wang, Shigehiro Nagataki, Da-Hai Yan and Jian-Cheng Wang A&A, 659 (2022) A184 Published online: 24 March 2022 DOI: 10.1051/0004-6361/202142051