CP Violating Contribution to Delta Gamma in the B_s System from Mixing with a Hidden Pseudoscalar

Recent evidence for a CP violating asymmetry in the semileptonic decays of B_s mesons cannot be accommodated within the Standard Model. Such an asymmetry can be explained by new physics contributions to Delta B=2 components of either the mass matrix or the decay matrix. We show that mixing with a hidden pseudoscalar meson with a mass around 5 GeV can result in a new CP violating contribution to the mixing and can resolve several anomalies in this system including the width difference, the average width and the charge asymmetry. We also discuss the effects of the hidden meson on other b physics observables, and present viable decay modes for the hidden meson. We make predictions for new decay channels of B hadrons, which can be tested at the Tevatron, the LHC and B-factories.