Measurement of b-hadron masses

Measurements of b-hadron masses are performed with the exclusive decay modes B+ --> J/psi K+, B-0 --> J/psi K-0*, B-0 --> J/psi K-S(0), B-s(0) --> j/psi phi and Lambda(0)(b) --> J/psi Lambda using all integrated luminosity of 35 pb(-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/psi --> mu(+)mu(-) decays and verified to be known to a relative precision of 2 x 10(-4) using other two-body decays. The results are more precise than previous measurements, particularly ill the case of the B-s(0) and Lambda(0)(b) masses. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.