| Title: |
Shining light on the dark sector: search for axion-like particles and other new physics in photonic final states with FASER |
| Authors: |
FASER collaboration; Mammen Abraham, Roshan; Kose, Umut; Rubbia, André; Sgalaberna, Davide |
| Source: |
Journal of High Energy Physics, 2025 (1) |
| Publisher Information: |
Springer |
| Publication Year: |
2025 |
| Collection: |
ETH Zürich Research Collection |
| Subject Terms: |
Beyond Standard Model; Dark matter; Forward Physics; Hadron-Hadron Scattering |
| Description: |
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$_a$WW, 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. ; ISSN:1126-6708 ; ISSN:1029-8479 ; ISSN:1029-8479 |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/application/pdf |
| Language: |
English |
| Relation: |
info:eu-repo/semantics/altIdentifier/wos/001509788900001; https://hdl.handle.net/20.500.11850/732813 |
| DOI: |
10.3929/ethz-b-000732813 |
| Availability: |
https://hdl.handle.net/20.500.11850/732813; https://doi.org/10.3929/ethz-b-000732813 |
| Rights: |
info:eu-repo/semantics/openAccess ; http://creativecommons.org/licenses/by/4.0/ ; Creative Commons Attribution 4.0 International |
| Accession Number: |
edsbas.E58664D0 |
| Database: |
BASE |