Vacuum energy in non-supersymmetric quasi-realistic heterotic-string vacua with fixed moduli Eman Basaad, Luke A. Detraux, Alonzo R. Diaz Avalos, Alon E. Faraggi and Benjamin Percival Eur. Phys. J. C, 85 2 (2025) 209 Published online: 24 February 2025 DOI: 10.1140/epjc/s10052-024-13733-2