muon g factor $g_{\mu}$
- $-2.002 331 8418(13)$
| Numerical value | $-2.002 331 8418$ |
| Standard uncertainty | $+0.000 000 0013$ |
| Relative standard uncertainty | $6.3 \times 10^{-10}$ |
define $a_{\mu} = (g-2)_{\mu}/2$, which differs from the SM prediction by
$$\delta a_\mu = a_\mu^{{\rm exp}} - a_\mu^{{\rm SM}} = (279\pm 76)\times 10^{-11}$$
corresponding to a $3.7 \sigma$ deviation.