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A<sc>bstract</sc> The results of a model-independent search for the pair production of new bosons within a mass range of 0.21< m <60 GeV, are presented. This study utilizes events with a four-muon final state. We use two data sets, comprising 41.5 fb−1and 59.7 fb−1of proton-proton collisions at$$ \sqrt{s} $$ = 13 TeV, recorded in 2017 and 2018 by the CMS experiment at the CERN LHC. The study of the 2018 data set includes a search for displaced signatures of a new boson within the proper decay length range of 0< cτ <100 mm. Our results are combined with a previous CMS result, based on 35.9 fb−1of proton-proton collisions at$$ \sqrt{s} $$ = 13 TeV collected in 2016. No significant deviation from the expected background is observed. Results are presented in terms of a model-independent upper limit on the product of cross section, branching fraction, and acceptance. The findings are interpreted across various benchmark models, such as an axion-like particle model, a vector portal model, the next-to-minimal supersymmetric standard model, and a dark supersymmetric scenario, including those predicting a non-negligible proper decay length of the new boson. In all considered scenarios, substantial portions of the parameter space are excluded, expanding upon prior results.
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This content will become publicly available on January 1, 2026
Shining light on the dark sector: search for axion-like particles and other new physics in photonic final states with FASER
A<sc>bstract</sc> 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,gaWW, around 10−4GeV−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)Bgauge 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.
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- PAR ID:
- 10612111
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Publisher / Repository:
- JHEP
- Date Published:
- Journal Name:
- Journal of High Energy Physics
- Volume:
- 2025
- Issue:
- 1
- ISSN:
- 1029-8479
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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