Long-Lived BLSSM Particles at the LHC

TL;DR

This paper explores the detection prospects of long-lived supersymmetric particles predicted by the BLSSM extension at the LHC, focusing on their unique displaced vertex and charged track signatures.

Contribution

It identifies specific long-lived particles in the BLSSM model and analyzes their collider signatures, highlighting their potential observability at the LHC.

Findings

Neutral LLPs produce displaced di-leptons with large impact parameters.

Charged LLPs generate slow-moving charged tracks with high momentum.

Production cross sections are around 1 fb, making detection feasible.

Abstract

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 non-vanishing 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 ${\cal O}(1)~{\rm fb}$. Thus, probing these particles at the LHC is quite plausible. In addition, we find that the displaced di-lepton 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.