Anomalous CP-Violation in B_s-Bbar_s Mixing Due to a Light Spin-One Particle

Understand

The recent measurement of the like-sign dimuon charge asymmetry in semileptonic b-hadron decays by the D0 Collaboration is about 3 sigmas away from the standard-model prediction, hinting at the presence of CP-violating new physics in the mixing of B_s mesons.

• We consider the possibility that this anomalous result arises from the contribution of a light spin-1 particle.
• Taking into account various experimental constraints, we find that the effect of such a particle with mass below the b-quark mass can yield a prediction consistent with the anomalous D0 measurement within its one-sigma range.