Constraining ALP-Top Interaction from the Chromoelectric Dipole Moment of the Top Quark

2025/07/16 by Subhadip Bisal, Bisal, Subhadip · 2 citations
Engineering · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #Superconducting Materials and Applications

paper · pdf · doi:10.48550/arxiv.2507.12570

openalex publication_date 2025/07/16 · openalex created_date 2025/10/16 · openalex updated_date 2026/07/28

Abstract

The couplings of axion-like particles (ALPs) to Standard Model fermions are proportional to the fermion masses, making the interaction with the top quark particularly significant. In this study, we consider an ALP that is a mixture of CP-even and CP-odd components, thereby introducing CP violation. This CP violation, in turn, gives rise to electric dipole moments (EDMs) of quarks and leptons, as well as chromoelectric dipole moments (CEDMs) of quarks. We compute the one-loop and two-loop contributions to the top quark CEDM induced by the ALP. In our calculation, we treat the external gluon as off-shell with momentum q² ≠ 0, derive the analytical results, and finally evaluate the top quark CEDM at q² = m_t², corresponding to the top quark pole mass. This value is relevant for subsequent calculations of the EDMs of the neutron and mercury. By applying current experimental bounds on EDMs and CEDMs, we derive constraints on the ALP-top quark coupling, with the strongest limit coming from the neutron EDM.

Citations

• The LHC as an Axion-Photon Collider
• Electroweak baryogenesis in 2HDM without EDM cancellation
• Two-Loop Contributions to the Anomalous Chromomagnetic Dipole Moment of the Top Quark in Two-Higgs-Doublet Models
• Top-philic ALP phenomenology at the LHC
• Top-philic ALP phenomenology at the LHC: the elusive mass-window
• Global Analysis of the ALP Effective Theory
• Constraining off-shell production of axion-like particles with Zγ and WW differential cross-section measurements
• The landscape of QCD axion models
• New Axion Searches at Flavor Factories
• New experimental approaches in the search for axion-like particles
• The Low-Energy Frontier of Particle Physics
• Review of Particle Physics

Cited by

• A global analysis of ALP-mediated multiboson production at the LHC
• Probing the coupling of axions to tops and gluons with LHC measurements

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