The LSP Stability and New Higgs Signals at the LHC

Abstract

The fate of R-parity in the context of the minimal supersymmetric standard model is a central issue which has profound implications for particle physics and cosmology. In this article we discuss the possibility of testing the mechanism responsible for the stability of the lightest supersymmetric particle at the Large Hadron Collider (LHC). The simplest theoretical framework where R-parity conservation can be explained dynamically allows for two types of B-L models. In the first scenario the new Higgses decay mainly into two right-handed neutrinos giving rise to exotic lepton number violating signals together with displaced vertices. In the second model one could have peculiar channels with multileptons and/or multiphotons in the final state. In both cases, the local B-L gauge symmetry is broken at the TeV scale and the discovery of the new Higgs bosons may be possible at the LHC. We investigate in detail the production mechanisms for the Higgs bosons relevant for the LHC and the key decays which would shed light on how R-parity is conserved. These results may help to understand the link between the cold dark matter of the universe and the missing energy that could be observed at the LHC if supersymmetry is realized in nature.Comment: 39 pages, minor corrections, to appear in Physical Review