  We study the bottom $\Lambda_b(6146)^0$ baryon, newly discovered by the LHCb
Collaboration. By adopting an interpolating current of $(L_{\rho},
L_{\lambda})=(0,2)$ type and $D$-wave nature with spin-parity quantum numbers
$J^P=\frac{3}{2}^+$ for this heavy bottom baryon, we calculate its mass and
residue. Using these spectroscopic parameters, we also investigate its dominant
decays $\Lambda_b(6146)^0\rightarrow\Sigma_b\pi$ and
$\Lambda_b(6146)^0\rightarrow\Sigma^*_b\pi$ and estimate the width of
$\Lambda_b(6146)^0$ obtained via these channels. The obtained mass,
$m_{\Lambda_b}=(6144\pm 68)$~MeV is in accord nicely with the experimental
data. The width obtained via the dominant channels is also consistent with the
experimental data of LHCb collaboration. We calculate the spectroscopic
parameters and the same decay channels for the $c$-partner of
$\Lambda_b(6146)^0$ state, namely $\Lambda_c(2860)^+$, as well. We compare the
obtained results with the existing theoretical predictions as well as
experimental data. The results indicate that the state $\Lambda_b(6146)^0$ and
its charmed-partner $\Lambda_c(2860)^+$ can be considered as $1D$-wave baryons
with $J^P=\frac{3}{2}^+$.
