${{\mathit n}}$ MEAN LIFE INSPIRE search

Limits on lifetimes for $\mathit bound$ neutrons are given in the section``p PARTIAL MEAN LIVES.”

We average eight of the best nine measurements, those made with ultracold neutrons (UCN's). If we include the one in-beam measurement with a comparable error (YUE 2013), we get $878.6$ $\pm0.6$ s, where the scale factor is now 2.2.

For a recent discussion of the long-standing disagreement between in-beam and UCN results, see CZARNECKI 2018 (Physical Review Letters 120 202002 (2018)). For a full review of all matters concerning the neutron lifetime until about 2010, see WIETFELDT 2011, F.E. Wietfeldt and G.L. Greene, “The neutron lifetime,” Reviews of Modern Physics 83 1173 (2011).
S017T
VALUE (s) DOCUMENT ID TECN  COMMENT
$\bf{ 878.4 \pm0.5}$ OUR AVERAGE  Error includes scale factor of 1.8.
$877.75$ $\pm0.28$ ${}^{+0.22}_{-0.16}$
GONZALEZ
2021
CNTR UCN asym. magnetic trap
$878.3$ $\pm1.6$ $\pm1.0$
EZHOV
2018
CNTR UCN magneto-gravit. trap
$877.7$ $\pm0.7$ ${}^{+0.4}_{-0.2}$ 1
PATTIE
2018
CNTR UCN asym. magnetic trap
$881.5$ $\pm0.7$ $\pm0.6$
SEREBROV
2018
CNTR UCN gravitational trap
$880.2$ $\pm1.2$ 2
ARZUMANOV
2015
CNTR UCN double bottle
$882.5$ $\pm1.4$ $\pm1.5$ 3
STEYERL
2012
CNTR UCN material bottle
$880.7$ $\pm1.3$ $\pm1.2$
PICHLMAIER
2010
CNTR UCN material bottle
$878.5$ $\pm0.7$ $\pm0.3$
SEREBROV
2005
CNTR UCN gravitational trap
• • • We do not use the following data for averages, fits, limits, etc. • • •
$887$ $\pm14$ ${}^{+7}_{-3}$ 4
WILSON
2021
CNTR space-based ${{\mathit n}}$ rate
$887.7$ $\pm1.2$ $\pm1.9$ 5
YUE
2013
CNTR In-beam ${{\mathit n}}$, trapped ${{\mathit p}}$
$881.6$ $\pm0.8$ $\pm1.9$ 6
ARZUMANOV
2012
CNTR See ARZUMANOV 2015
$886.3$ $\pm1.2$ $\pm3.2$
NICO
2005
CNTR See YUE 2013
$886.8$ $\pm1.2$ $\pm3.2$
DEWEY
2003
CNTR See NICO 2005
$885.4$ $\pm0.9$ $\pm0.4$
ARZUMANOV
2000
CNTR See ARZUMANOV 2012
$889.2$ $\pm3.0$ $\pm3.8$
BYRNE
1996
CNTR Penning trap
$882.6$ $\pm2.7$ 7
MAMPE
1993
CNTR UCN material bottle
$888.4$ $\pm3.1$ $\pm1.1$ 8
NESVIZHEVSKII
1992
CNTR UCN material bottle
$888.4$ $\pm2.9$
ALFIMENKOV
1990
CNTR See NESVIZHEVSKII 1992
$893.6$ $\pm3.8$ $\pm3.7$
BYRNE
1990
CNTR See BYRNE 1996
$878$ $\pm27$ $\pm14$
KOSSAKOWSKI
1989
TPC Pulsed beam
$887.6$ $\pm3.0$
MAMPE
1989
CNTR See STEYERL 2012
$877$ $\pm10$
PAUL
1989
CNTR Magnetic storage ring
$876$ $\pm10$ $\pm19$
LAST
1988
SPEC Pulsed beam
$891$ $\pm9$
SPIVAK
1988
CNTR Beam
$903$ $\pm13$
KOSVINTSEV
1986
CNTR UCN material bottle
$937$ $\pm18$ 9
BYRNE
1980
CNTR
$875$ $\pm95$
KOSVINTSEV
1980
CNTR
$881$ $\pm8$
BONDARENKO
1978
CNTR See SPIVAK 1988
$918$ $\pm14$
CHRISTENSEN
1972
CNTR
1  PATTIE 2018 uses a new technique, with a semi-toroidal magneto-gravitational asymmetric trap and a novel in situ ${{\mathit n}}$-detector.
2  ARZUMANOV 2015 is a reanalysis of their $2008 - 2010$ dataset, with improved systematic corrections of of ARZUMANOV 2000 and ARZUMANOV 2012.
3  STEYERL 2012 is a detailed reanalysis of neutron storage loss corrections to the raw data of MAMPE 1989, and it replaces that value.
4  WILSON 2021 extract the value from the flux of ${{\mathit n}}$ escaping the moon using data from the Lunar Prospector Neutron Spectrometer.
5  YUE 2013 differs from NICO 2005 in that a different and better method was used to measure the neutron density in the fiducial volume. This shifted the lifetime by +1.4 seconds and reduced the previously largest source of systematic uncertainty by a factor of five.
6  ARZUMANOV 2012 reanalyzes its systematic corrections in ARZUMANOV 2000 and obtains this corrected value.
7  IGNATOVICH 1995 calls into question some of the corrections and averaging procedures used by MAMPE 1993. The response, BONDARENKO 1996, denies the validity of the criticisms.
8  The NESVIZHEVSKII 1992 measurement has been withdrawn by A. Serebrov.
9  The BYRNE 1980 measurement has been withdrawn (J.$~$Byrne, private communication, 1990).

           neutron mean life (s)
  References:
GONZALEZ 2021
PRL 127 162501 Improved neutron lifetime measurement with UCN$\tau$
WILSON 2021
PR C104 045501 Measurement of the free neutron lifetime using the neutron spectrometer on NASA's Lunar Prospector mission
EZHOV 2018
JETPL 107 671 Measurement of the neutron lifetime with ultra-cold neutrons stored in a magneto-gravitational trap
PATTIE 2018
SCI 360 627 Measurement of the neutron lifetime using a magneto-gravitational trap and in situ detection
SEREBROV 2018
PR C97 055503 Neutron lifetime measurements with a large gravitational trap for ultracold neutrons
Also
JETPL 106 623 New measurement of the neutron lifetime with a large gravitational trap
ARZUMANOV 2015
PL B745 79 A Measurement of the Neutron Lifetime using the Method of Storage of Ultracold Neutrons and Detection of Inelastically up-Scattered Neutrons
YUE 2013
PRL 111 222501 Improved Determination of the Neutron Lifetime
ARZUMANOV 2012
JETPL 95 224 Analysis and Correction of the Measurement of the Neutron Lifetime
STEYERL 2012
PR C85 065503 Quasielastic Scattering in the Interaction of Ultracold Neutrons with a Liquid Wall and Application in a Reanalysis of the Mambo I Neutron-Lifetime Experiment
PICHLMAIER 2010
PL B693 221 Neutron Lifetime Measurement with the UCN Trap-in-Trap MAMBO II
NICO 2005
PR C71 055502 Measurement of the Neutron Lifetime by Counting Trapped Protons in a Cold Neutron Beam
SEREBROV 2005
PL B605 72 Measurement of the Neutron Lifetime using a Gravitational Trap and a Low-Temperature Fomblin Coating
Also
SPU 48 867 Neutron Lifetime Measurements using Gravitationally Trapped Ultracold Neutrons
DEWEY 2003
PRL 91 152302 Measurement of the Neutron Lifetime Using a Proton Trap
ARZUMANOV 2000
PL B483 15 Neutron Life Time Value Measured by Storing Ultracold Neutrons with Detection of Inelastically Scattering Neutrons
BYRNE 1996
EPL 33 187 A Revised Value for the Neutron Lifetime Measured Using a Penning Trap
MAMPE 1993
JETPL 57 82 Measurement of the Lifetime of Neutron by Means of Keeping of UCN with Registration of Inelastically Scattered Neutrons
NESVIZHEVSKII 1992
JETP 75 405 Result of the Neutron Lifetime Measurement in the Gravitational Trap Experiment and Analysis of the Experimental Errors
ALFIMENKOV 1990
JETPL 52 373 Results of Neutron Lifetime Measurements with Gravitational UCN Trap
BYRNE 1990
PRL 65 289 Measurement of the Neutron Lifetime by Counting Trapped Protons
KOSSAKOWSKI 1989
NP A503 473 Neutron Lifetime Measurement with a Helium-Filled Time Projection Chamber
MAMPE 1989
PRL 63 593 Neutron Lifetime Measured with Stored Ultracold Neutrons
PAUL 1989
ZPHY C45 25 Measurement of the Neutron Lifetime in a Magnetic Storage Ring
LAST 1988
PRL 60 995 Pulsed Beam Neutron Lifetime Measurement
SPIVAK 1988
JETP 67 1735 Neutron Lifetime in KIAE Experiment
KOSVINTSEV 1986
JETPL 44 571 The Measurement of the Neutron's Life Time by Ultracold Neutron Save Method
BYRNE 1980
PL 92B 274 A New Measurement of the Neutron Lifetime
KOSVINTSEV 1980
JETPL 31 236 Application of Ultracold Neutrons for Neutron Lifetime Measurement
BONDARENKO 1978
JETPL 28 303 Measurement of Neutron Halflife
Also
Smolenice Conf. Measurement of Neutron Halflife
CHRISTENSEN 1972
PR D5 1628 Free Neutron $\beta $ Decay Halflife