  Measurements of the associated production of a Z boson with at least one jet
originating from a b quark in proton-proton collisions at sqrt(s) = 8 TeV are
presented. Differential cross sections are measured with data collected by the
CMS experiment corresponding to an integrated luminosity of 19.8 inverse
femtobarns. Z bosons are reconstructed through their decays to electrons and
muons. Cross sections are measured as a function of observables characterizing
the kinematics of the b jet and the Z boson. Ratios of differential cross
sections for the associated production with at least one b jet to the
associated production with any jet are also presented. The production of a Z
boson with two b jets is investigated, and differential cross sections are
measured for the dijet system. Results are compared to theoretical predictions,
testing two different flavour schemes for the choice of initial-state partons.
