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

${{\mathit p}}$

$I(J^P)$ = $1/2(1/2^{+})$ 
${{\mathit p}}$ MASS (atomic mass units u)   $1.007276466621 \pm0.000000000053$ u 
${{\mathit p}}$ MASS (MeV)   $938.27208816 \pm0.00000029$ MeV 
$\vert {\mathit m}_{{{\mathit p}}}−{\mathit m}_{{{\overline{\mathit p}}}}\vert /{\mathit m}_{{{\mathit p}}}$   $<7 \times 10^{-10}$   CL=90.0%
${{\overline{\mathit p}}}/{{\mathit p}}$ CHARGE-TO-MASS RATIO, $\vert {\mathit q_{{{\overline{\mathit p}}}}\over {\mathit m}_{{{\overline{\mathit p}}}}}\vert /({\mathit q_{{{\mathit p}}}\over {\mathit m}_{{{\mathit p}}}}$)   $1.000000000003 \pm0.000000000016$  
($\vert {\mathit q_{{{\overline{\mathit p}}}}\over {\mathit m}_{{{\overline{\mathit p}}}}}\vert -{\mathit q_{p}\over {\mathit m}_{{{\mathit p}}}})/{\mathit q_{{{\mathit p}}}\over {\mathit m}_{{{\mathit p}}}}$   $(0.3 \pm1.6) \times 10^{-11}$  
$\vert \mathit q_{{{\mathit p}}}~+~\mathit q_{{{\overline{\mathit p}}}}\vert /{{\mathit e}}$   $<7 \times 10^{-10}$   CL=90.0%
$\vert {{\mathit q}_{{{p}}}}+{{\mathit q}_{{{e}}}}\vert /{{\mathit e}}$   $<1 \times 10^{-21}$  
${{\mathit p}}$ MAGNETIC MOMENT   $2.7928473446 \pm0.0000000008$ $\mu _{\mathit N}$ 
${{\overline{\mathit p}}}$ MAGNETIC MOMENT   $-2.792847344 \pm0.000000004$ $\mu _{\mathit N}$ 
(${\mathit \mu}_{{{\mathit p}}}$ $+$ ${\mathit \mu}_{{{\overline{\mathit p}}}}$) $/$ $\mu _{{{\mathit p}}}$   $(2 \pm4) \times 10^{-9}$  
${{\mathit p}}$ ELECTRIC DIPOLE MOMENT   $<2.1 \times 10^{-25}$ $\mathit e~$cm 
${{\mathit p}}$ ELECTRIC POLARIZABILITY ${{\mathit \alpha}_{{{p}}}}$   $0.00112 \pm0.00004$ fm${}^{3}$ 
${{\mathit p}}$ MAGNETIC POLARIZABILITY ${{\mathit \beta}_{{{p}}}}$   $(2.5 \pm0.4) \times 10^{-4}$ fm${}^{3}$ (S = 1.2)
${{\mathit p}}$ CHARGE RADIUS   $0.8409 \pm0.0004$ fm 
${{\mathit p}}$ MAGNETIC RADIUS   $0.851 \pm0.026$ fm 
${{\mathit p}}$ MEAN LIFE   $>9 \times 10^{29}$ years  CL=90.0%
${{\overline{\mathit p}}}$ MEAN LIFE
See the ``Note on Nucleon Decay'' in our 1994 edition (Phys. Rev. $\mathbf {D50}$, 1173) for a short review.
The ``partial mean life'' limits tabulated here are the limits on ${{\mathit \tau}}/B_{\mathit i}$, where ${{\mathit \tau}}$ is the total mean life and B$_{\mathit i}$ is the branching fraction for the mode in question. For ${{\mathit N}}$ decays, ${{\mathit p}}$ and ${{\mathit n}}$ indicate proton and neutron partial lifetimes.