Anomalies, representations, and self-supervision
Barry M. Dillon, Luigi Favaro, Friedrich Feiden, Tanmoy Modak, Tilman Plehn
SciPost Phys. Core 7, 056 (2024) · published 16 August 2024
- doi: 10.21468/SciPostPhysCore.7.3.056
- Submissions/Reports
Abstract
We develop a self-supervised method for density-based anomaly detection using contrastive learning, and test it using event-level anomaly data from CMS ADC2021. The AnomalyCLR technique is data-driven and uses augmentations of the background data to mimic non-Standard-Model events in a model-agnostic way. It uses a permutation-invariant Transformer Encoder architecture to map the objects measured in a collider event to the representation space, where the data augmentations define a representation space which is sensitive to potential anomalous features. An AutoEncoder trained on background representations then computes anomaly scores for a variety of signals in the representation space. With AnomalyCLR we find significant improvements on performance metrics for all signals when compared to the raw data baseline.
Supplementary Information
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Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 2 Barry M. Dillon,
- 1 Luigi Favaro,
- 1 Friedrich Feiden,
- 1 3 Tanmoy Modak,
- 1 Tilman Plehn
- 1 Ruprecht-Karls-Universität Heidelberg / Heidelberg University
- 2 University of Ulster / University of Ulster [UU]
- 3 Indian Institute of Science Education and Research Berhampur / Indian Institute of Science Education and Research Berhampur [IISER]