Speaker
Description
During the second long shutdown of the LHC at CERN, the most important Phase-1 upgrade within the ATLAS experiment was replacement of the two inner endcap stations of the Muon Spectrometer, with the New Small Wheels (NSW). Consisting of two novel detector technologies, the small-strip Thin Gap Chambers (sTGC) and the resistive strips Micromegas (MM), the NSW is targeting the rejection of fake muons at the endcap region between pseudorapidity $1.3<|\eta|<2.4$. Furthermore, thanks to the excellent muon tracking and the improved triggering capability NSW contributes to the identification of muons coming from the interaction point with high precision. Following an extensive effort during 2023 to finalise the commissioning of the new detectors, by 2024 both technologies were integrated successfully into the ATLAS data acquisition, reconstruction, simulation and trigger, offering a significant reduction of the ATLAS Level-1 trigger rate and further reducing the readout dead-time. Despite the demanding challenges and increased luminosity delivered by LHC, the ATLAS NSW completed important milestones and now demonstrates its readiness towards the end of the Run3 data-taking period of LHC. This contribution will present an overview of the advancements made within 2024, followed by a detailed report of the NSW performance in terms of tracking and triggering, using data recorded from pp collisions at 13.6 TeV.
| Primary experiment | ATLAS Muon Spectrometer |
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