Charmless $b$-meson and $b$-baryon decays at LHCb

The latest LHCb results for charmless $b$-meson and $b$-baryon decays, using Run I data collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, are presented. The search for charmless three-body decays of the $\Lambda_b^0$ and $\Xi_b^0$ baryons to the final states $\Lambda h^+h^{\prime -}$ ($h^{(\prime)} = \pi$ or $K$) results in the first observation of $\Lambda_b^0 \to \Lambda K^+\pi^-$ and $\Lambda_b^0 \to \Lambda K^+K^-$ decays and measurements of their branching fractions and \CP asymmetries, as well as evidence of the $\Lambda_b^0 \to \Lambda \pi^+\pi^-$ decay and limits on the branching fractions of $\Xi_b^0$ baryon decays. The first observation of $\Lambda_b^0 \to \Lambda \phi$ decay is also reported and the branching fraction and triple-product asymmetries are measured. The search for $\Lambda_b^0 \to \Lambda \eta'$ and $\Lambda_b^0 \to \Lambda \eta$ decays yields evidence for the latter and upper limits on the former. A measurement of the branching fraction of $B_s^0 \rightarrow \phi \phi$ decay and a limit on the $B^0 \rightarrow \phi \phi$ mode are also presented. The decay $B_{s}^{0} \to K_{\rm{S}}^{0} K^{*}(892)^{0}$ is observed for the first time and its branching fraction measured.