Pseudoscalar glueball mass: a window on three-gluon interactions E. V. Souza, M. N. Ferreira, A. C. Aguilar, J. Papavassiliou, C. D. Roberts and S.-S. Xu Eur. Phys. J. A, 56 1 (2020) 25 Published online: 28 January 2020 DOI: 10.1140/epja/s10050-020-00041-y