F. J. M. Farley, J. Bailey, R. C. A. Brown, M. Giesch, H. J¨ostlein, S. van der Meer, E. Picasso and M. Tannenbaum, Nuovo Cimento 45, 281-286 (1966), "The anomalous magnetic moment of the negative muon"
Above, they measured muon decay under many thousands of "G" from acceleration in a storage...