  Weak decays of heavy-quark baryons offer an attractive laboratory to search
for effects beyond the Standard Model (SM), complementary to searches in meson
decays. However, the properties of these baryons are not well understood. In
particular, the $\Omega^-_b$ baryon is the least studied weakly decaying $b$
baryon. Therefore, the most precise determination of the $\Omega^{-}_{b}$
baryon mass is reported, using $\Omega^-_b \to J/\psi \Omega^-$ decays at the
LHCb experiment. In addition, the relative production rate of the $\Omega^-_b$
baryon in $pp$ collisions at the LHC is determined for the first time. These
quantities are crucial to predict and measure branching fractions of
$\Omega^{-}_{b}$ baryon decays.
