Higgs Decays as a Window into the Dark Sector

Understand

A light vector boson, Z_d, associated with a "dark sector" U(1)_d gauge group has been introduced to explain certain astrophysical observations as well as low energy laboratory anomalies.

• In such models, the Higgs boson may decay into X+Z_d, where X=Z, Z_d or \gamma.
• Here, we provide estimates of those decay rates as functions of the Z_d coupling through either mass-mixing (e.g.
• via an enlarged Higgs mechanism) or through heavy new fermion loops and examine the implied LHC phenomenology.