Long-Lived Slepton in the Coannihilation Region and Measurement of Lepton Flavour Violation at LHC

TL;DR

This paper explores the phenomenology of long-lived sleptons in the MSSM when the mass difference with the neutralino is small, highlighting their potential to reveal lepton flavor violation at the LHC.

Contribution

It demonstrates that long-lived sleptons can serve as a probe for lepton flavor violation, enabling significant improvements in bounds through LHC measurements.

Findings

Long-lived sleptons produce distinctive LHC signatures.

Measurement of slepton lifetime can reveal lepton flavor violation.

Potential to improve leptonic mass insertion bounds by over five orders of magnitude.

Abstract

When the mass difference between the lightest slepton and the lightest neutralino is smaller than the tau mass, the lifetime of the lightest slepton in the constrained Minimal Supersymmetric Standard Model (MSSM) increases in many orders of magnitude with respect to typical lifetimes of other supersymmetric particles. In a general MSSM, the lifetime of the lightest slepton is inversely proportional to the square of the intergenerational mixing in the slepton mass matrices. Such a long-lived slepton would produce a distinctive signature at LHC and a measurement of its lifetime would be relatively simple. Therefore, the long-lived slepton scenario offers an excellent opportunity to study lepton flavour violation at ATLAS and CMS detectors in the LHC and an improvement of the leptonic mass insertion bounds by more than five orders of magnitude would be possible.