Measuring the Lifetime of Trapped Sleptons Using the General Purpose LHC Detectors

TL;DR

This paper proposes a method to measure the lifetime of trapped sleptons at the LHC, enabling testing of supergravity models with long-lived charged particles without additional trapping devices.

Contribution

It introduces a novel approach to determine slepton lifetime and SUSY cross-section from detector data, sensitive to cosmologically relevant lifetimes.

Findings

Lifetime measurement accuracy of 5% after 3 years of data collection.

Method can detect stau lifetimes around 37 days.

No need for extra trapping volumes for slepton detection.

Abstract

In supergravity where the gravitino is the lightest supersymmetric particle (LSP), the next-to-lightest supersymmetric particle (NLSP) decays to the gravitino with a naturally long lifetime (10^4 - 10^8). However, cosmological constraints favour charged sleptons with lifetimes below a year as the natural NLSP candidate. For this scenario we report a method to accurately determine the slepton lifetime and SUSY cross-section from observation of the decays of sleptons trapped in the material comprising the main detector (ATLAS, CMS). A measurement of the lifetime to 5% is possible after 3 years at nominal luminosity and running conditions. This method is sensitive to the cosmologically preferred stau lifetime of ~37 days and does not require the use of ancillary trapping volumes.