Higgs boson decays to four fermions through an abelian hidden sector

Abstract

We consider a generic abelian hidden sector that couples to the Standard Model only through gauge-invariant renormalizable operators. This allows the exotic Higgs boson to mix with the Standard Model Higgs boson, and the exotic abelian gauge boson to mix with the Standard Model hypercharge gauge boson. One immediate consequence of spontaneous breaking of the hidden sector gauge group is the possible decay of the lightest Higgs boson into four fermions through intermediate exotic gauge bosons. We study the implications of this decay for Higgs boson phenomenology at the Fermilab Tevatron Collider and the CERN Large Hadron Collider. Our emphasis is on the four lepton final state.

Figures (4)

• Figure 1: Branching ratio of $h\to {Z^{\prime}} {Z^{\prime}}$ as a function of $s_h^2$ for various ${M_{Z^\prime}}$ and $M_h$, with $\eta = 10^{-4}$. Benchmark points are shown in Table \ref{['bchmrk.TBL']}.
• Figure 2: Branching ratio of ${Z^{\prime}}$ into two body final states as a function of ${M_{Z^\prime}}$ with $c_h^2=0.5$ and $\eta=10^{-4}$.
• Figure 3: Total cross section of the process $pp \rightarrow h \rightarrow {Z^{\prime}}{Z^{\prime}} \rightarrow 4l$ at LHC as a function of $\sin^2\theta_h$. From top to bottom, lines correspond to points A,C,B,D,E,F. No cuts have been applied.
• Figure 4: $M_{e^+ e^- \mu^+ \mu^-}$ (in GeV) versus number of events (arbitrary luminosity) for benchmark point D at the Tevatron (top), and point F at the LHC (bottom). No cuts are applied yet. Black solid line represents $h \rightarrow XX \rightarrow 4l$ signal, red crossed $ZZ(\gamma) \rightarrow 4l$, and blue circled $h \rightarrow ZZ \rightarrow 4l$.