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

INSPIRE search
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combination in TIESINGA 2021 includes data from HEISSE 2017 , but does not include updates in HEISSE 2019 , which superseded HEISSE 2017 .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 Superseded by HEISSE 2019 .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:
FINK 2021
PRL 127 243001
TIESINGA 2021
RMP 93 025010 CODATA recommended values of the fundamental physical constants: 2018
HEISSE 2019
PR A100 022518 High-precision mass spectrometer for light ions
HEISSE 2017
PRL 119 033001 High-Precision Measurement of the Proton's Atomic Mass
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