Online-compatible Unsupervised Non-resonant Anomaly Detection
This addresses the need for model-agnostic anomaly detection in high-energy physics, providing a first online-compatible method for non-resonant anomalies.
The paper tackles the problem of unsupervised non-resonant anomaly detection in particle physics by proposing a complete strategy that includes both signal sensitivity and data-driven background estimation, achieving excellent performance on signals from the ADC2021 data challenge.
There is a growing need for anomaly detection methods that can broaden the search for new particles in a model-agnostic manner. Most proposals for new methods focus exclusively on signal sensitivity. However, it is not enough to select anomalous events - there must also be a strategy to provide context to the selected events. We propose the first complete strategy for unsupervised detection of non-resonant anomalies that includes both signal sensitivity and a data-driven method for background estimation. Our technique is built out of two simultaneously-trained autoencoders that are forced to be decorrelated from each other. This method can be deployed offline for non-resonant anomaly detection and is also the first complete online-compatible anomaly detection strategy. We show that our method achieves excellent performance on a variety of signals prepared for the ADC2021 data challenge.