Reconstruction of stop quark mass at the LHC

TL;DR

This paper demonstrates a method to reconstruct the stop quark mass at the LHC using cascade decay simulations, achieving about 10% precision assuming prior knowledge of related particle masses.

Contribution

The study applies a cascade mass reconstruction approach to simulated LHC data, providing a new technique for measuring the stop quark mass with realistic detector effects.

Findings

Stop quark mass reconstructed with ~10% precision.

Method relies on prior knowledge of gluino, slepton, and neutralino masses.

Simulation of 400k SUSY events at 14 TeV with detector effects.

Abstract

The cascade mass reconstruction approach was applied to simulated production of the lightest stop quark at the LHC in the cascade decay $\tilde{g} \to \sTop \, \Top \to \tilde{\chi}_{2}^{0} \, \Top \, \Top \to \tilde{\ell}_{R} \, \ell \, \Top \, \Top \to \tilde{\chi}_{1}^{0} \, \ell \, \ell \, \Top \, \Top$ with top quarks decaying into hadrons. The stop quark mass was reconstructed assuming that the masses of gluino, slepton and of the two lightest neutralinos were reconstructed in advance. A data sample set for the SU3 model point containing 400k SUSY events was generated which corresponded to an integrated luminosity of about 20 $\rm fb^{-1}$ at 14 TeV. These events were passed through the AcerDET detector simulator, which parametrized the response of a generic LHC detector. The mass of the $\tilde{t}_{1}$ was reconstructed with a precision of about $10\%$.