${{\mathit N}}$ BARYONS($\mathit S$ = 0, $\mathit I$ = 1/2) ${{\mathit p}}$, ${{\mathit N}^{+}}$ = ${\mathit {\mathit u}}$ ${\mathit {\mathit u}}$ ${\mathit {\mathit d}}$; ${{\mathit n}}$, ${{\mathit N}^{0}}$ = ${\mathit {\mathit u}}$ ${\mathit {\mathit d}}$ ${\mathit {\mathit d}}$ INSPIRE search

#### ${{\mathit n}}$

$I(J^P)$ = $1/2(1/2^{+})$
We have omitted some results that have been superseded by later experiments. See our earlier editions. Anyone interested in the neutron should look at these two review articles: D. Dubbers and M.G. Schmidt, “The neutron and its role in cosmology and particle physics,” Reviews of Modern Physics 83 1111 (2011); and F.E. Wietfeldt and G.L. Greene, “The neutron lifetime,” Reviews of Modern Physics 83 1173 (2011).
 See related review: Baryon Decay Parameters
 ${{\mathit n}}$ MASS (atomic mass units u) $1.0086649159 \pm0.0000000005$ u
 ${{\mathit n}}$ MASS (MeV) $939.565413 \pm0.000006$ MeV
 ${{\overline{\mathit n}}}$ MASS $939.49 \pm0.05$ MeV
 (${\mathit m}_{{{\mathit n}}}–{\mathit m}_{{{\overline{\mathit n}}}}$ )/ ${\mathit m}_{{{\mathit n}}}$ $(9 \pm6) \times 10^{-5}$
 ${\mathit m}_{{{\mathit n}}}–{\mathit m}_{{{\mathit p}}}$ $1.2933321 \pm0.0000005$ MeV
 ${{\mathit n}}$ MEAN LIFE $879.4 \pm0.6$ s (S = 1.6)
 ${{\mathit n}}$ MAGNETIC MOMENT $-1.9130427 \pm0.0000005$ $\mu _{\mathit N}$
 ${{\mathit n}}$ ELECTRIC DIPOLE MOMENT $<1.8 \times 10^{-26}$ $\mathit e~$cm  CL=90.0%
 ${{\mathit n}}$ MEAN-SQUARE CHARGE RADIUS $-0.1161 \pm0.0022$ fm${}^{2}$ (S = 1.3)
 ${{\mathit n}}$ MAGNETIC RADIUS $0.864 {}^{+0.009}_{-0.008}$ fm
 ${{\mathit n}}$ ELECTRIC POLARIZABILITY ${{\mathit \alpha}_{{n}}}$ $0.00118 \pm0.00011$ fm${}^{3}$
 ${{\mathit n}}$ MAGNETIC POLARIZABILITY ${{\mathit \beta}_{{n}}}$ $(3.7 \pm1.2) \times 10^{-4}$ fm${}^{3}$
 ${{\mathit n}}$ CHARGE $(-2 \pm8) \times 10^{-22}$ $\mathit e$
LIMIT ON ${{\mathit n}}{{\overline{\mathit n}}}$ OSCILLATIONS
 Mean Time for ${{\mathit n}}{{\overline{\mathit n}}}$ Transition $>8.6 \times 10^{7}$ s  CL=90.0%
 LIMIT ON ${{\mathit n}}{{\mathit n}^{\,'}}$ OSCILLATIONS $> 448$ s  CL=90.0%
${{\mathit n}}$ $\rightarrow$ ${{\mathit p}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}_{{e}}}$ DECAY PARAMETERS
 $\lambda {}\equiv{\mathit g}_{{{\mathit A}}}$ $/$ ${\mathit g}_{{{\mathit V}}}$ $-1.2754 \pm0.0013$  (S = 2.7)
 ${{\mathit e}^{-}}$ ASYMMETRY PARAMETER $\mathit A$ $-0.11958 \pm0.00021$  (S = 1.2)
 ${{\overline{\mathit \nu}}_{{e}}}$ ASYMMETRY PARAMETER $\mathit B$ $0.9807 \pm0.0030$
 PROTON ASYMMETRY PARAMETER $\mathit C$ $-0.2377 \pm0.0026$
 ${{\mathit e}}-{{\overline{\mathit \nu}}_{{e}}}$ ANGULAR CORRELATION COEFFICIENT $\mathit a$ $-0.1044 \pm0.0008$
 $\phi _{\mathit AV}$, PHASE OF ${\mathit g}_{{{\mathit A}}}$ RELATIVE TO ${\mathit g}_{{{\mathit V}}}$ $180.017 \pm0.026$ $^\circ{}$
 TRIPLE CORRELATION COEFFICIENT $\mathit D$ $(-1.2 \pm2.0) \times 10^{-4}$
 TRIPLE CORRELATION COEFFICIENT $\mathit R$ $0.004 \pm0.013$
 FIERZ INTERFERENCE TERM $\mathit b$ $0.017 \pm0.020$
 $\Gamma_{1}$ ${{\mathit p}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}_{{e}}}$ $(100)\%$ 1
 $\Gamma_{2}$ ${{\mathit p}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}_{{e}}}{{\mathit \gamma}}$ [1] $(9.2\pm{0.7})\times 10^{-3}$ 1
 $\Gamma_{3}$ hydrogen-atom ${{\overline{\mathit \nu}}_{{e}}}$ $<2.7\times 10^{-3}$ CL=95% 1
 FOOTNOTES