The muon's mass is obtained from the muon-electron mass ratio as determined from the measurement of Zeeman transition frequencies in muonium ( ${{\mathit \mu}^{+}}{{\mathit e}^{-}}$ atom). Since the electron's mass is most accurately known in u, the muon's mass is also most accurately known in u. The conversion factor to MeV has approximately the same relative uncertainty as the mass of the muon in u. In this datablock we give the result in u, and in the following datablock in MeV.

VALUE (u) DOCUMENT ID TECN  COMMENT $0.1134289259$ $\pm0.0000000025$ TIESINGA 2021 RVUE 2018 CODATA value • • We do not use the following data for averages, fits, limits, etc. • • $0.1134289257$ $\pm0.0000000025$ MOHR 2016 RVUE 2014 CODATA value $0.1134289267$ $\pm0.0000000029$ MOHR 2012 RVUE 2010 CODATA value $0.1134289256$ $\pm0.0000000029$ MOHR 2008 RVUE 2006 CODATA value $0.1134289264$ $\pm0.0000000030$ MOHR 2005 RVUE 2002 CODATA value $0.1134289168$ $\pm0.0000000034$ 1 MOHR 1999 RVUE 1998 CODATA value $0.113428913$ $\pm0.000000017$ 2 COHEN 1987 RVUE 1986 CODATA value 1  MOHR 1999 make use of other 1998 CODATA entries below. 2  COHEN 1987 make use of other 1986 CODATA entries below.

References:

TIESINGA 2021 RMP 93 025010 CODATA recommended values of the fundamental physical constants: 2018 MOHR 2016 RMP 88 035009 CODATA Recommended Values of the Fundamental Physical Constants: 2014 MOHR 2012 RMP 84 1527 CODATA Recommended Values of the Fundamental Physical Constants: 2010 MOHR 2008 RMP 80 633 CODATA Recomended Values of the Fundamental Physical Constants: 2006 MOHR 2005 RMP 77 1 NIST Constants MOHR 1999 JPCRD 28 1713 CODATA Recommended Values of the Fundamental Physical Constants: 1998; Also RMP 72 351 CODATA Recommended Values of the Fundamental Physical Constants: 1998 COHEN 1987 RMP 59 1121 CODATA Fundamental Physical Constants 1986 Adjustments