Spectroscopy and decay properties of $b$-hadrons with the ATLAS experiment

ATLAS has performed searches and accurate measurement of heavy hadrons, with results including the first observation of the $chi_b(3P)$ Bottomonium states and one of the most accurate measurements of the $\Lambda_b$ lifetime. New results in this program are discussed, including the measurement of the parity violating asymmetry parameter $\alpha_b$ in $\Lambda_b \to \Lambda J/\psi$, obtained from the study of angular correlations in the $p \pi^- \mu^+ \mu^-$ final state. Results are compared with the latest theoretical calculations and models.