# Dimensionless mass-to-charge ratio of the electron

Afonso Campos
In SI units, the mass-to-charge ratio of the electron is

$$\frac{m_{e}}{|q_{e}|} = \frac{9.11 \times 10^{-31} \text{kg}}{1.6 \times 10^{-19} \text{C}} = 5.7 \times 10^{-12} \text{kg/C}.$$

In which system of units do we have the dimensionless mass-to-charge ratio

$$\frac{m_{e}}{|q_{e}|} \simeq 4.9 \times 10^{-22}?$$

For reference, see the text in [2] of page 6 of the paper https://arxiv.org/abs/1705.06287.