Bottomonium spectroscopy with mixing of etab states and a light CP-odd Higgs boson.

The mass of the eta(b)(1S), measured recently by the BABAR Collaboration, is significantly lower than expected from QCD predictions for the Upsilon(1S)-eta(b)(1S) hyperfine splitting. We suggest that the observed eta(b)(1S) mass is shifted downwards due to a mixing with a CP-odd Higgs boson A with a mass m(A) in the range 9.4-10.