Long-lived B − L symmetric SSM particles at the LHC

We investigate the collider signatures of neutral and charged long-lived particles (LLPs), predicted by the supersymmetric B−L extension of the Standard Model (BLSSM), at the Large Hadron Collider (LHC). The BLSSM is a natural extension of the minimal supersymmetric Standard Model (MSSM) that can account for nonvanishing neutrino masses. We show that the lightest right-handed sneutrino can be the lightest supersymmetric particle (LSP), while the next-to-the LSP (NLSP) is either the lightest left-handed sneutrino or the left-handed stau, which are natural candidates for the LLPs. We analyze the displaced vertex signature of the neutral LLP (the lightest left-handed sneutrino) and the charged tracks associated with the charged LLP (the left-handed stau). We show that the production cross sections of our neutral and charged LLPs are relatively large, namely of order O(1) fb. Thus, probing these particles at the LHC is quite plausible. In addition, we find that the displaced dilepton associated with the lightest left-handed sneutrino has a large impact parameter that discriminates it from other SM leptons. We also emphasize that the charged track associated with the left-handed stau has a large momentum with slow moving charged tracks, hence it is distinguished from the SM background, and therefore it can be accessible at the LHC.