Identifying the Origin of Longevity of Metastable Stau at the LHC

TL;DR

This paper investigates the reasons behind the long-lived nature of the stau in supersymmetric models at the LHC, analyzing event topologies and decay patterns to identify the underlying scenario.

Contribution

It introduces a method to distinguish the origin of stau longevity in different supersymmetric scenarios using LHC event analysis.

Findings

Event topology analysis can differentiate between the three scenarios.

Decay patterns of stopping staus provide clues to their origin.

Identification of the longevity mechanism is feasible at the LHC.

Abstract

In the framework of the supersymmetric standard model, the lighter stau often becomes long-lived. Such longevity of the stau is realized in three well-motivated scenarios: (A) the stau is the next-to-lightest supersymmetric particle (NLSP) and the gravitino is the lightest supersymmetric particle (LSP), (B) the stau is the LSP and R-parity is slightly violated, and (C) the stau is NLSP, the neutralino is the LSP, and the their masses are degenerate. We study the event topology and the decay of the stopping stau at the hadron calorimeter at the LHC, and show that it is possible to identify the reason why the stau becomes long-lived.