  We combine searches by the CDF and D0 Collaborations for the associated
production of a Higgs boson with a W or Z boson and subsequent decay of the
Higgs boson to a bottom-antibottom quark pair. The data, originating from
Fermilab Tevatron p-pbar collisions at sqrt{s}=1.96 TeV, correspond to
integrated luminosities of up to 9.7 fb^-1. The searches are conducted for a
Higgs boson with mass in the range 100-150 GeV/c^2. We observe an excess of
events in the data compared with the background predictions, which is most
significant in the mass range between 120 and 135 GeV/c^2. The largest local
significance is 3.3 standard deviations, corresponding to a global significance
of 3.1 standard deviations. We interpret this as evidence for the presence of a
new particle consistent with the standard model Higgs boson, which is produced
in association with a weak vector boson and decays to a bottom-antibottom quark
pair.
