2022/04/21 by Victor Baules, Baules, Victor, Nobuchika Okada +1 · 1 citation
Computer Science · Physics and Astronomy · #Computational Physics and Python Applications #Cosmology and Gravitation Theories #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2204.10265
openalex publication_date 2022/04/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider a classically conformal U(1) gauge extension of the Standard Model (SM), in which the U(1) gauge symmetry is radiatively broken by the Coleman-Weinberg mechanism. This breaking triggers the electroweak (EW) symmetry breaking through a mixed quartic coupling between the U(1) Higgs field and the SM Higgs doublet. For two Higgs boson mass eigenstates after the symmetry breaking, h1 (SM-like Higgs boson) and h2 (SM singlet-like Higgs boson), we calculate the Higgs boson trilinear coupling (g_h1 h2 h2) in the model by setting the Higgs boson mass spectrum to be Mh1 > 2 Mh2. For a common Higgs mass spectrum and mixing angle between two Higgs fields, we find that g_h1 h2 h2 in the classically conformal model is highly suppressed compared to that calculated for the conventional Higgs potential, where the U(1) and EW symmetry breaking originate from the negative squared masses for the Higgs fields at the tree-level. Thus, this coupling suppression is a striking nature of the radiative origin of EW symmetry breaking. We then consider how to distinguish this origin at the proposed International Linear Collider (ILC) via precise measurements of anomalous SM Higgs boson couplings and the search for anomalous SM Higgs boson decay h1 → h2 h2 followed by h2 → b b. We conclude that once the anomalous couplings are measured at the ILC, the observation of the anomalous Higgs boson decay is promising in the conventional Higgs potential, while this decay process is highly suppressed and undetectable for the classically conformal model.