The Phase-1 Upgrade of the ATLAS Level-1 Endcap Muon Trigger

TL;DR

The paper describes the development and implementation of a new trigger logic and hardware upgrade for the ATLAS Level-1 endcap muon trigger to handle increased luminosity in Run 3, maintaining physics acceptance.

Contribution

It introduces a novel trigger logic and a new trigger board (NSL) that integrate multiple detector signals and reduce trigger rates effectively for Run 3.

Findings

Trigger rate reduced below required level

New trigger logic successfully implemented on FPGA

Enhanced sensitivity to new physics with increased luminosity

Abstract

For Run 3 (from 2021), the LHC will undergo a significant increase in instantaneous luminosity to 1.5 times its current value which will lead to larger collected statistics and an enhanced sensitivity to new physics. The Phase-1 upgrade of the ATLAS Level-1 endcap muon trigger is essential to keep the physics acceptance at Run 3. A new trigger logic to take coincidence with detectors inside and outside the magnetic field is described and is shown to reduce the trigger rate to lower than the required level in Run 3. A new trigger board, NSL, to integrate all the information from various detectors, has been developed, and the implementation of the new logic on the FPGA has been successfully demonstrated.