QUARKS INSPIRE   JSON PDGID:
Q005

${\mathit {\mathit b}}$

$I(J^P)$ = $0(1/2^{+})$ 
  Charge = $−{1\over 3}$ $\mathit e$ Bottom = $−$1
${\mathit {\mathit b}}$-QUARK MASS [1] $4.183$ $\pm0.004$ GeV 
 
${\mathit m}_{{{\mathit b}}}/{\mathit m}_{{{\mathit s}}}$ MASS RATIO $53.88$ $\pm0.12$  
 
[1] The ${{\mathit c}}$- and ${{\mathit b}}$-quark masses are estimated from charmonium, bottomonium, ${{\mathit D}}$, and ${{\mathit B}}$ masses. They are the ``running'' masses in the $\overline{\rm{}MS}$ scheme.