Il nuovo cimento / C 45, 9 (2022). doi:10.1393/ncc/i2022-22009-8 special issue: "SoUP 2021" 1. INFN International School on Underground Physics : Theory and Experiments, SOUP 2021, online, 2021-06-28-2021-07-02 Il nuovo cimento / C 9 (2022). doi:10.1393/ncc/i2022-22009-8 The 1st INFN School on Underground Physics, SoUP 2021, Online, Italy, 2021-06-28-2021-07-02