Studies on η meson production and the C-parity violating decay η → π0 e+ e− with WASA-at-COSY Nils Hüsken, Florian Bergmann, Kay Demmich, Alfons Khoukaz and Karsten Sitterberg EPJ Web Conf., 113 (2016) 05023 Published online: 25 March 2016 DOI: 10.1051/epjconf/201611305023