Search for Beyond the Standard Model physics with anomaly detection in multilepton final states in pp collisions at $$\sqrt{s}=13~\textrm{TeV}$$ with the ATLAS detector

The European Physical Journal C 2026 Open access

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Authors: G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz, Y. Abulaiti, B. S. Acharya
+88 more A. Ackermann, C. Adam Bourdarios, L. Adamczyk, S. V. Addepalli, M. J. Addison, J. Adelman, A. Adiguzel, T. Adye, A. A. Affolder, Y. Afik, M. N. Agaras, A. Aggarwal, C. Agheorghiesei, F. Ahmadov, S. Ahuja, S. Ahuja, X. Ai, G. Aielli, A. Aikot, M. Ait Tamlihat, B. Aitbenchikh, M. Akbiyik, T. P. A. Åkesson, A. V. Akimov, D. Akiyama, N. N. Akolkar, S. Aktas, G. L. Alberghi, J. Albert, U. Alberti, P. Albicocco, G. L. Albouy, S. Alderweireldt, Z. L. Alegria, M. Aleksa, I. N. Aleksandrov, C. Alexa, T. Alexopoulos, F. Alfonsi, M. Algren, M. Alhroob, B. Ali, H. M. J. Ali, S. Ali, S. W. Alibocus, M. Aliev, G. Alimonti, W. Alkakhi, C. Allaire, B. M. M. Allbrooke, D. R. Allen, J. S. Allen, J. F. Allen, P. P. Allport, A. Aloisio, F. Alonso, C. Alpigiani, Z. M. K. Alsolami, A. Alvarez Fernandez, M. Alves Cardoso, M. G. Alviggi, M. Aly, Y. Amaral Coutinho, A. Ambler, C. Amelung, M. Amerl, C. G. Ames, T. Amezza, D. Amidei, B. Amini, K. Amirie, A. Amirkhanov, S. P. Amor Dos Santos, K. R. Amos, D. Amperiadou, S. An, C. Anastopoulos, T. Andeen, J. K. Anders, A. C. Anderson, A. Andreazza, S. Angelidakis, A. Angerami, A. V. Anisenkov, A. Annovi, C. Antel, E. Antipov, M. Antonelli
DOI: 10.1140/epjc/s10052-025-15218-2
Cited by: 1
References: 109

Abstract

Abstract A model-agnostic search for Beyond the Standard Model physics is presented, targeting final states with at least four light leptons (electrons or muons). The search regions are separated by event topology and unsupervised machine learning is used to identify anomalous events in the full 140 fb $$^{-1}$$ - 1 of proton–proton collision data collected with the ATLAS detector during Run 2. No significant excess above the Standard Model background expectation is observed. Model-agnostic limits are presented in each topology, along with limits on several benchmark models including vector-like leptons, wino-like charginos and neutralinos, or smuons. Limits are set on the flavourful vector-like lepton model for the first time.

Fields of Study & Subjects

Particle physics theoretical and experimental studies Computational Physics and Python Applications Particle Detector Development and Performance

Publication details

Journal / source
The European Physical Journal C
Publisher
Springer Science and Business Media LLC
Volume
86
Issue
3
Publication date
11 March 2026
Language
EN