Measurement of the annihilation decay rate of 2 3S1 positronium R. E. Sheldon, T. J. Babij, B. A. Devlin-Hill, L. Gurung and D. B. Cassidy EPL, 132 1 (2020) 13001 Published online: 02 November 2020 DOI: 10.1209/0295-5075/132/13001