Quark flavor violation and axion-like particles from top-quark decays at the LHC

Abstract

We study axion-like particles (ALPs) with quark-flavor-violating couplings at the LHC. Specifically, we focus on the theoretical scenario with ALP-top-up and ALP-top-charm interactions, in addition to the more common quark-flavor-diagonal couplings. The ALPs can thus originate from decays of top quarks which are pair produced in large numbers at the LHC, and then decay to jets. If these couplings to the quarks are tiny and the ALPs have $\mathcal{O}(10)$ GeV masses, they are long-lived, leading to signatures of displaced vertex plus multiple jets, which have the advantage of suppression of background events at the LHC. We recast a recent ATLAS search for the same signature and reinterpret the results in terms of bounds on the long-lived ALP in our theoretical scenario. We find that the LHC with the full Run 2 dataset can place stringent limits, while at the future high-luminosity LHC with 3 ab${}^{-1}$ integrated luminosity stronger sensitivities are expected.

v1: 16 pages plus references, 2 figures, 11 tables; v2: 19 pages plus refs, 2 figures, 11 tables, new appendix B explaining the recast of top+jet and top+MET searches and their bounds now shown in figure 1, conclusions unchanged, matches the published version in JHEP

References in corpus (19)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• An Introduction to PYTHIA 8.2
• FeynRules - Feynman rules made easy
• A standard format for Les Houches Event Files
• Collider Probes of Axion-Like Particles
• Flaxion: a minimal extension to solve puzzles in the standard model
• The Low-Energy Effective Theory of Axions and ALPs
• Flavor probes of axion-like particles
• Quark Flavor Phenomenology of the QCD Axion
• Expression of Interest for the CODEX-b Detector
• Charming ALPs
• Extending the constraint for axion-like particles as resonances at the LHC and laser beam experiments
• Probing axion-like particles with $\gamma \gamma$ final states from vector boson fusion processes at the LHC
• On the IR/UV flavour connection in non-universal axion models
• Photon initiated single top quark production via flavor-changing neutral currents at the LHC
• Top Secrets: Long-Lived ALPs in Top Production
• Precise tests of the axion coupling to tops
• Flavored axion in the UV-complete Froggatt-Nielsen models
• The Flavor of QCD Axion Dark Matter

Cited by in corpus (6)

• Searching for heavy neutral leptons coupled to axion-like particles at the LHC far detectors and SHiP
• Exploring Axion-Like Particle Couplings through Single Top $tW$-Channel and Top Pair Production at the LHC
• The LHC as an Axion-Photon Collider
• Searching for long-lived light neutralinos and axionlike particles at the SHiNESS experiment
• Long-Lived HNLs via ALP Portal at the LHC
• Searching for long-lived axion-like particles via displaced vertices at the HL-LHC