The Liquid Argon Jet Trigger of the H1 Experiment at HERA

TL;DR

The Liquid Argon Jet Trigger in the H1 experiment at HERA is a real-time system that identifies energy clusters within 800 ns, significantly improving trigger efficiency for electrons and jets since 2006.

Contribution

This paper introduces a novel real-time cluster algorithm implemented in hardware for the H1 experiment, enabling faster and more efficient event triggering.

Findings

Operated successfully since 2006

Reduced trigger thresholds for electrons and jets

Implemented in 800 ns real-time hardware

Abstract

The Liquid Argon Jet Trigger, installed in the H1 experiment at HERA, implements in 800 ns a real-time cluster algorithm by finding local energy maxima, summing their immediate neighbors, sorting the resulting "jets" by energy, and applying topological conditions. It operated since the year 2006 and drastically reduced the thresholds for triggering on electrons and jets.