A first study of Hidden Valley models at the LHC

Abstract: New stable particles with fairly low masses could exist if the coupling to the Standard Model is weak, and with suitable parameters they might be possible to produce at the LHC. Here we study a selection of models with the new particles being charged under a new gauge group, either U(1) or SU(N). In the Abelian case there will be radiation of gammavs, which decay back into the SM. In the non-Abelian case the particles will undergo hadronization into mesons like states piv/rhov that subsequently decays. We consider three different scenarios for interaction between the new sector and the SM sector and perform simulations using a Hidden Valley model previously implemented in PYTHIA. In this study we illustrate how one can distinguish the different models and measure different parameters of the models under conditions like those at the LHC.