Measurement of b-hadron masses

Measurements of b-hadron masses are performed with the exclusive decay modes B ⁺→J/ψK ⁺, B ⁰→J/ψK ⁺, B0→J/ψKS0, Bs0→J/ψφ and Λb0→J/ψΛ using an integrated luminosity of 35pb ^-1 collected in pp collisions at a centre-of-mass energy of 7 TeV by the LHCb experiment. The momentum scale is calibrated with J/ψ→μ ⁺μ ^- decays and verified to be known to a relative precision of 2 ×10 ^-4 using other two-body decays. The results are more precise than previous measurements, particularly in the case of the Bs0 and Λb0 masses.