A new high-precision upper limit of direct α-decays from the Hoyle state in 12C D. Dell’Aquila, I. Lombardo, G. Verde, M. Vigilante, L. Acosta, C. Agodi, F. Cappuzzello, D. Carbone, M. Cavallaro, S. Cherubini et al. (18 more) EPJ Web Conf., 165 (2017) 01020 Published online: 30 December 2017 DOI: 10.1051/epjconf/201716501020