open907siHighlighted by PRL as "Editors' Suggestion".We report four narrow peaks in the Ξ0b K− mass spectrum obtained using pp collisions at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb^−1 recorded by the LHCb experiment. Referring to these states by their mass, the mass values are m[Ωb(6316)−] = 6315.64 ± 0.31 ± 0.07 ± 0.50 MeV, m[Ωb(6330)−] = 6330.30 ± 0.28 ± 0.07 ± 0.50 MeV, m[Ωb(6340)−] = 6339.71 ± 0.26 ± 0.05 ± 0.50 MeV, m[Ωb(6350)−] = 6349.88 ± 0.35 ± 0.05 ± 0.50 MeV, where the uncertainties are statistical, systematic, and the last is due to the knowledge of the Ξ0b mass. The natural widths of the three lower mass states are consistent with zero, and the 90% confidence-level uppe...