Search for the η-mesic Helium bound state with the WASA-at-COSY facilityMagdalena Skurzok, Wojciech Krzemień, Oleksandr Rundel and Pawel MoskalEPJ Web of Conferences, 117 (2016) 02005DOI: https://doi.org/10.1051/epjconf/201611702005