nuclear magneton

https://doi.org/10.1351/goldbook.N04236
Electromagnetic fundamental physical constant \(\mu _{\text{N}}=\frac{m_{\text{e}}}{m_{\text{p}}}\ \mu _{\text{B}}=5.050\ 7866(17)\times 10^{-27}\ \text{J T}^{-1}\), where \(m_{\text{e}}\) is the electron rest mass, \(m_{\text{p}}\) the proton rest mass and \(\mu _{\text{B}}\) the Bohr magneton.
Source:
CODATA Bull., 1986, 63, 1. (https://doi.org/10.6028/jres.092.010)