Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

T: Fachverband Teilchenphysik

T 10: Axions/ALPS I

T 10.3: Vortrag

Montag, 16. März 2026, 16:45–17:00, KH 01.013

Search for Higgs decays into long-lived Axion-Like Particles with the ATLAS Experiment — •Janek Both, Volker Büscher, Christian Schmitt, and Emanuel Meuser — Johannes Gutenberg-Universität

Axion-Like Particles (ALPs) or more generally, pseudoscalars that are gauge singlets under the Standard Model gauge group, appear in many well-motivated extensions of the Standard Model. In scenarios where the ALP couples to the Higgs boson, collider searches can provide sensitivity to ALPs in the GeV range and thus offer a complementary approach to other experiments that mainly focus on lighter ALPs. Depending on the ALP lifetime, it might decay displaced from the primary vertex inside the calorimeters of the ATLAS detector. Such a decay leads to an exotic signature that clearly differs from promptly produced backgrounds, but also challenges conventional reconstruction and analysis methods.

In this talk, a search for Higgs boson decays into long-lived ALPs is presented. The analysis makes use of a graph neural network classifier that identifies ALP decays into photons within the ATLAS calorimeters. The analysis uses Run-3 data and a data driven background estimation. The search improves on the existing Run-2 analysis that focuses on promptly decaying ALPs.

Keywords: Higgs Physics; BSM Physics; Axion-like Particles; Long-lived Particles