First operation of undoped CsI directly coupled with SiPMs at 77 K Keyu Ding, Jing Liu, Yongjin Yang and Dmitry Chernyak Eur. Phys. J. C, 82 4 (2022) 344 Published online: 20 April 2022 DOI: 10.1140/epjc/s10052-022-10289-x