Search for pair production of massive particles decaying into three quarks with the ATLAS detector in sqrt(s) = 7 TeV pp collisions at the LHC

TL;DR

This paper searches for new massive particles decaying into three quarks using ATLAS data at 7 TeV, setting limits on gluino masses within a supersymmetry model with R-parity violation.

Contribution

It introduces a dual-channel analysis optimized for different gluino mass ranges, employing innovative jet selection and invariant mass techniques to improve sensitivity.

Findings

No significant excess over Standard Model background

Limits set on gluino mass in R-parity violating SUSY

Analysis techniques applicable to future searches

Abstract

A search is conducted for hadronic three-body decays of a new massive coloured particle in sqrt(s) = 7 TeV pp collisions at the LHC using an integrated luminosity of 4.6/fb collected by the ATLAS detector. Supersymmetric gluino pair production in the context of a model with R-parity violation is used as a benchmark scenario. The analysis is divided into two search channels, each optimised separately for their sensitivity to high-mass and low-mass gluino production. The first search channel uses a stringent selection on the transverse momentum of the six leading jets and is performed as a counting experiment. The second search channel focuses on low-mass gluinos produced with a large boost. Large-radius jets are selected and the invariant mass of each of the two leading jets is used as a discriminant between the signal and the background. The results are found to be consistent with Standard Model expectations and limits are set on the allowed gluino mass.