1. The nuclear magneton (symbol μN) is a physical constant of magnetic moment, defined in SI units by: μ N = e ℏ 2 m p {\displaystyle \mu _{\text{N}}={{e\hbar } \over {2m_{\text{p}}}}} and in Gaussian CGS units by: μ N = e ℏ 2 m p c {\displaystyle \mu _{\text{N}}={{e\hbar } \over {2m_{\text{p}}c}}} where: e is the... from wikipedia.org