An investigation of the and heavy quark mass dependence in the MSHT20 global PDF analysisT. Cridge, L. A. Harland-Lang, A. D. Martin and R. S. ThorneEur. Phys. J. C, 81 8 (2021) 744DOI: https://doi.org/10.1140/epjc/s10052-021-09533-7