Echoes of a Hidden Valley at Hadron Colliders

Abstract

We consider examples of ``hidden-valley'' models, in which a new confining gauge group is added to the standard model. Such models often arise in string constructions, and elsewhere. The resulting (electrically-neutral) bound states can have low masses and long lifetimes, and could be observed at the LHC and Tevatron. Production multiplicities are often large. Final states with heavy flavor are common; lepton pairs, displaced vertices and/or missing energy are possible. Accounting for LEP constraints, we find LHC production cross-sections typically in the 1-100 fb range, though they can be larger. It is possible the Higgs boson could be discovered at the Tevatron through rare decays to the new particles.

Figures (5)

• Figure 1: Partial spectrum and decay modes in the two-light-flavor regime (left) and one-light-flavor regime (right); the latter is partly guesswork.
• Figure 2: Tree-level v-quark production cross-section in fb versus $m_{Z'}$, for different $m_{Z'}/g'$; here $n_v=3$, $k=0$, $q_+=-2$, and $\Lambda_v,m_U,m_C\ll m_{Z'}$.
• Figure 3: A possible event in the two-light-flavor regime; note $\pi_v^\pm$ is electrically neutral and invisible.
• Figure 4: A possible event in the one-light-flavor regime.
• Figure 5: $X\bar{X}$ pair production with associated v-glueballs, for a stable $X$ in the adjoint of $G_v$; the $Xg_v$ bound state resembles a stable gluino.