${{\mathit p}}$ MASS (atomic mass units u)

INSPIRE   JSON  (beta) PDGID:
S016AMU
The mass is known more precisely in u (atomic mass units) than in MeV. See the next data block.
VALUE (u) DOCUMENT ID TECN  COMMENT
$\bf{ 1.007276466621 \pm0.000000000053}$ OUR EVALUATION  2018 CODATA
$1.007276466574$ $\pm0.000000000010$ 1
FINK
2021
SPEC Penning trap
$1.007276466621$ $\pm0.000000000053$ 2
TIESINGA
2021
RVUE 2018 CODATA value
• • We do not use the following data for averages, fits, limits, etc. • •
$1.007276466598$ $\pm0.000000000033$ 3
HEISSE
2019
SPEC Penning Trap
$1.007276466583$ $\pm0.000000000032$ 4
HEISSE
2017
SPEC See HEISSE 2019
$1.007276466879$ $\pm0.000000000091$
MOHR
2016
RVUE 2014 CODATA value
$1.007276466812$ $\pm0.000000000090$
MOHR
2012
RVUE 2010 CODATA value
$1.00727646677$ $\pm0.00000000010$
MOHR
2008
RVUE 2006 CODATA value
$1.00727646688$ $\pm0.00000000013$
MOHR
2005
RVUE 2002 CODATA value
$1.00727646688$ $\pm0.00000000013$
MOHR
1999
RVUE 1998 CODATA value
$1.007276470$ $\pm0.000000012$
COHEN
1987
RVUE 1986 CODATA value
1  FINK 2021 simultaneously measure the cyclotron frequencies of an ${{\mathit H}_{{{2}}}^{+}}$ ion and a deuteron in a coupled magnetron orbit. The proton mass is extracted using the precise deuteron mass value.
2  The 2018 CODATA combination in TIESINGA 2021 includes data from HEISSE 2017, but does not include updates in HEISSE 2019, which superseded HEISSE 2017. Consequently, we do not average HEISSE 2019 and TIESINGA 2021. Updating the 2018 CODATA combination to use HEISSE 2019 would shift the central value for the proton mass upwards by less than half a standard deviation. Therefore, we take the 2018 CODATA result in TIESINGA 2021 as the recommended value for the proton mass.
3  The value is an update of HEISSE 2017; the result is shifted by $1.5 \times 10^{-11}$ u, corresponding to 0.45 ${{\mathit \sigma}}$ due to the corrected motional temperatures of the particles. The statistical and total systematic uncertainties are given as 16 and 29 in the last two digits.
4  The statistical and systematic errors are 15 and 29 in the last two places of the value. Superseded by HEISSE 2019.
References