Long-lived stop at the LHC with or without R-parity

L Covi,F Dradi

doi:10.1088/1475-7516/2014/10/039

Abstract

We consider scenarios of gravitino LSP and DM with stop NLSP both within R-parity conserving and R-parity violating supersymmetry (RPC and RPV SUSY, respectively). We discuss cosmological bounds from Big Bang Nucleosynthesis (BBN) and the gravitino abundance and then concentrate on the signals of long-lived stops at the LHC as displaced vertices or metastable particles. Finally we discuss how to distinguish R-parity conserving and R-parity breaking stop decays if they happen within the detector and how to suppress SM backgrounds.

Highlights

It is well known that cosmology provides evidence for physics beyond the Standard Model (SM), since in the SM there is no viable candidate for Dark Matter (DM)
We have studied in this paper the reach of the LHC in models with a stop Next-to-Lightest Supersymmetric Particle (NLSP) and gravitino Lightest Supersymmetric Particle (LSP), both for the case of R-parity conservation and violation
In both cases we expect the stop to have a long lifetime leading to the possibility of displaced vertices or metastable particles at the LHC

Summary

Introduction

It is well known that cosmology provides evidence for physics beyond the Standard Model (SM), since in the SM there is no viable candidate for Dark Matter (DM). Supersymmetry provides another possible DM candidate, the gravitino, which results from locally supersymmetric extensions of the standard model as gauge fermion of supergravity (SUGRA) [2, 3]. If it is not the LSP and not light, the gravitino causes grave cosmological problems since it can decay during or after primordial nucleosynthesis (BBN) and strong constraints on the gravitino abundance and the reheat temperature arise in such scenarios [4]. Underlying events can give rise to particles pointing to a secondary vertex, faking the presence of a long-lived particle

Objectives

Findings

Discussion

Conclusion