Shining light on the dark sector: search for axion-like particles and other new physics in photonic final states with FASER

Article Article scientifique Article Shining light on the dark sector: search for axion-like particles and other new physics in photonic final states with FASER eng 2025-01-31 2025 FASER collaborator Antel Claire Geneva U. 924199 collaborator Bianchi Emma Julie Geneva U. 966261 collaborator Cadoux Franck Geneva U. 676514 Département de physique nucléaire et corpusculaire (FINUC) collaborator Cardella Roberto Calogero Geneva U. 948455 Département de physique nucléaire et corpusculaire (FINUC) collaborator Débieux Stéphane Geneva U. 690742 Département de physique nucléaire et corpusculaire (FINUC) Stéphane Debieux collaborator Favre Yannick Geneva U. 761433 Département de physique nucléaire et corpusculaire (FINUC) collaborator Fenoglio Carlo Alberto Geneva U. 990156 Département de physique nucléaire et corpusculaire (FINUC) collaborator Ferrere Didier Geneva U. 507742 Département de physique nucléaire et corpusculaire (FINUC) collaborator Gonzalez Sevilla Sergio Geneva U. 680902 Département de physique nucléaire et corpusculaire (FINUC) collaborator Iacobucci Giuseppe Geneva U. 752364 Département de physique nucléaire et corpusculaire (FINUC) collaborator Iodice Luca 0000-0002-8975-6589 Geneva U. 981202 Département de physique nucléaire et corpusculaire (FINUC) collaborator Kontaxakis Pantelis Geneva U. 989871 Département de physique nucléaire et corpusculaire (FINUC) collaborator Kugathasan Thanushan Geneva U. 403671 Département de physique nucléaire et corpusculaire (FINUC) collaborator Magliocca Chiara 0009-0009-4927-9253 Geneva U. 935399 collaborator Pizarro Medina Andrea Geneva U. 815874 Département de physique nucléaire et corpusculaire (FINUC) collaborator Milanesio Matteo 0000-0001-8778-9638 Geneva U. 962203 Département de physique nucléaire et corpusculaire (FINUC) collaborator Moretti Théo 0000-0001-7065-1923 Geneva U. 850018 Département de physique nucléaire et corpusculaire (FINUC) collaborator Paolozzi Lorenzo Geneva U. 831519 collaborator Sabater Iglesias Jorge Geneva U. 971670 collaborator Sfyrla Anna Geneva U. 584693 Département de physique nucléaire et corpusculaire (FINUC) collaborator Noshin Tarannum Noshin Geneva U. 960459 collaborator Theiner Ondrej Geneva U. 932039 collaborator Zambito Stefano Geneva U. 980555 Département de physique nucléaire et corpusculaire (FINUC) 10.1007/JHEP01(2025)199 1029-8479 2410.10363 https://link.springer.com/10.1007/JHEP01(2025)199 The first FASER search for a light, long-lived particle decaying into a pair of photons is reported. The search uses LHC proton-proton collision data at $ \sqrt{s} $ = 13.6 TeV collected in 2022 and 2023, corresponding to an integrated luminosity of 57.7 fb$^{−1}$. A model with axion-like particles (ALPs) dominantly coupled to weak gauge bosons is the primary target. Signal events are characterised by high-energy deposits in the electromagnetic calorimeter and no signal in the veto scintillators. One event is observed, compared to a background expectation of 0.44 ± 0.39 events, which is entirely dominated by neutrino interactions. World-leading constraints on ALPs are obtained for masses up to 300 MeV and couplings to the Standard Model W gauge boson, g$_{aWW}$, around 10$^{−4}$ GeV$^{−1}$, testing a previously unexplored region of parameter space. Other new particle models that lead to the same experimental signature, including ALPs coupled to gluons or photons, U(1)$_{B}$ gauge bosons, up-philic scalars, and a Type-I two-Higgs doublet model, are also considered for interpretation, and new constraints on previously viable parameter space are presented in this paper.[graphic not available: see fulltext] Beyond Standard Model Dark Matter Forward Physics Hadron-Hadron Scattering Dewey 500.2 34 Département de physique nucléaire et corpusculaire 132 false The journal of high energy physics 01 1 6b5cf62c-fc0a-40dd-9e71-e30df69d175a Article (Published version) Public Article_scientifique_from_unpaywall.pdf 7719233 application/pdf CC BY b6aa307e537642af2e16aff9d85485f52b02ee699ce64a6e0a3ddb4a046585fa openAccess Faculté des sciences / Section de physique / Département de physique nucléaire et corpusculaire

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Shining light on the dark sector: search for axion-like particles and other new physics in photonic final states with FASER	The journal of high energy physics			2025	5	8

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Bianchi, Emma Julie