PT Journal AU LHCb Collaboration (Aaij, Rea Martinez-Vidal, F Oyanguren, A Ruiz Valls, P Sanchez Mayordomo, C TI Observation of Lambda(0)(b) -> psi (2S)pK(-) and Lambda(0)(b) -> J/psi pi(+)pi(-)pK(-) decays and a measurement of the A(b)(0) baryon mass SO Journal of High Energy Physics JI J. High Energy Phys. PY 2016 BP 132 EP 22pp VL 05 IS 5 DI 10.1007/JHEP05(2016)132 LA English DE B physics; Flavor physics; Hadron-Hadron scattering (experiments); Particle and resonance production; Spectroscopy AB The decays Lambda(0)(b) -> psi(2S)pK(-) and Lambda(0)(b) -> J/psi pi(+)pi(-)pK(-) are observed in a data sample corresponding to an integrated luminosity of 3 fb(-1), collected in proton-proton collisions at 7 and 8 TeV centre-of-mass energies by the LHCb detector. The psi(2S) mesons are reconstructed through the decay modes psi(2S) -> mu(+)mu(-) and psi(2S) -> J/psi pi(+)pi(-) The branching fractions relative to that of Lambda(0)(b) -> J/psi pk(-) are measured to be [GRAPHICS] where the first uncertainties are statistical, the second are systematic and the third is related to the knowledge of J/psi and psi(2S) branching fractions. The mass of the Ai baryon is measured to be M(Lambda(0)(b)) = 5619.65 +/- 0.17 0.17 MeV/c(2), where the uncertainties are statistical and systematic. ER