${{\boldsymbol n}}$ ELECTRIC DIPOLE MOMENT INSPIRE search

A nonzero value is forbidden by both $\mathit T$ invariance and $\mathit P$ invariance. A number of early results have been omitted. See RAMSEY 1990 , GOLUB 1994 , and LAMOREAUX 2009 for reviews.

The results are upper limits on $\vert {{\mathit d}_{{n}}}\vert$.
VALUE ($10^{-25}$ $\mathit e~$cm) CL% DOCUMENT ID TECN  COMMENT
$\bf{<0.18}$ 90 1
 2020
MRS UCN
• • • We do not use the following data for averages, fits, limits, etc. • • •
$<0.22$ 95 2
 2017
${}^{199}\mathrm {Hg}$ atom EDM + theory
$<0.16$ 95
 2016
MRS ${}^{199}\mathrm {Hg}$ atom EDM + theory
$<0.30$ 90 3
 2015
MRS Supersedes BAKER 2006
$<0.55$ 90
 2015
MRS UCN's, h${{\mathit \nu}}$ = 2${{\mathit \mu}_{{n}}}$B $\pm$ 2${{\mathit d}_{{n}}}$E
$<0.55$ 90 4
 2014
MRS
$<0.29$ 90 5
 2006
MRS
$<0.63$ 90 6
 1999
MRS ${{\mathit d}}$ = ($-0.1$ $\pm0.36$) $\times 10^{-25}$
$<0.97$ 90
 1996
MRS
$<1.1$ 95
 1992
MRS See ALTAREV 1996
$<1.2$ 95
 1990
MRS See HARRIS 1999
$<2.6$ 95
 1986
MRS ${{\mathit d}}$ = ($-1.4$ $\pm0.6$) $\times 10^{-25}$
$0.3$ $\pm4.8$
 1984
MRS Ultracold neutrons
$<6$ 90
 1981
MRS ${{\mathit d}}$ = ($2.1$ $\pm2.4$) $\times 10^{-25}$
$<16$ 90
 1979
MRS ${{\mathit d}}$ = ($4.0$ $\pm7.5$) $\times 10^{-25}$
1  ABEL 2020 reports ${{\mathit d}}$ = ($0.0$ $\pm1.1$ $\pm0.2$) $\times 10^{-26}{{\mathit e}}~$cm value corresponding to the listed limit.
2  SAHOO 2017 develops theory to calculate this limit from the measured limit by GRANER 2016 of the ${}^{199}\mathrm {Hg}$ atom EDM.
3  PENDLEBURY 2015 reports ${{\mathit d}}$ = ($-0.21$ $\pm1.82$) $\times 10^{-26}{{\mathit e}}~$cm value corresponding to the listed limit.
4  SEREBROV 2014 includes the data of ALTAREV 1996 .
5  LAMOREAUX 2007 faults BAKER 2006 for not including in the estimate of systematic error an effect due to the Earth's rotation. BAKER 2007 replies (1) that the effect was included implicitly in the analysis and (2) that further analysis confirms that the BAKER 2006 limit is correct as is. See also SILENKO 2007 .
6  This HARRIS 1999 result includes the result of SMITH 1990 . However, the averaging of the results of these two experiments has been criticized by LAMOREAUX 2000 .
Conservation Laws:
 TIME REVERSAL ($\mathit T$) INVARIANCE , $\mathit CP$ INVARIANCE , PARITY ($\mathit P$) INVARIANCE
References:
 ABEL 2020
PRL 124 081803 Measurement of the permanent electric dipole moment of the neutron
 SAHOO 2017
PR D95 013002 Improved Limits on the Hadronic and Semi-Hadronic $\mathit CP$ Violating Parameters and Role of a Dark Force Carrier in the Electric Dipole Moment of ${}^{199}\mathrm {Hg}$
 GRANER 2016
PRL 116 161601 Reduced Limit on the Permanent Electric Dipole Moment of ${}^{199}\mathrm {Hg}$
 PENDLEBURY 2015
PR D92 092003 Revised Experimental upper Limit on the Electric Dipole Moment of the Neutron
 SEREBROV 2015
PR C92 055501 New Search for the Neutron Electric Dipole Moment with Ultracold Neutrons at ILL
 SEREBROV 2014
JETPL 99 4 New Measurements of the Neutron Electric Dipole Moment
 BAKER 2006
PRL 97 131801 Improved Experimental Limit on the Electric Dipole Moment of the Neutron
 HARRIS 1999
PRL 82 904 New Experimental Limit on the Electric Dipole Moment of the Neutron
 ALTAREV 1996
PAN 59 1152 Search for the Neutron Electric Dipole Moment
 ALTAREV 1992
PL B276 242 New Measurement of the Electric Dipole Moment of the Neutron
 SMITH 1990
PL B234 191 A Search for the Electric Dipole Moment of the Neutron
 ALTAREV 1986
JETPL 44 460 Search for an Electric Dipole Moment of the Neutron
 PENDLEBURY 1984
PL 136B 327 Search for a Neutron Electric Dipole Moment
 ALTAREV 1981
PL 102B 13 A New Upper Limit on the Electric Dipole Moment of the Neutron
 ALTAREV 1979
JETPL 29 730 Search for an Electric Dipole Moment of the Neutron by Means of the UltraCold Neutrons