Work

Recent B + → K + ν ν ¯ excess and muon g − 2 illuminating light dark sector with Higgs portal

Year: 2025

Type: article

Abstract: The Belle II collaboration recently announced that they observed the B + → K + ν ν ¯ decay process for the first time. However, their result encounters a 2.7 σ deviation from the Standard Model (SM) calculation. Additionally, Fermilab released new data on muon g − 2 away from the SM expectation with 5.1 σ . In this paper, we study the simplest UV-complete U ( 1 ) L μ − L τ -charged complex scalar dark matter (DM) model. Thanks to the existence of light dark Higgs boson and light dark photon, we can explain the observed relic density of DM and resolve the results reported by both Belle II and Fermilab experiments simultaneously. As a by-product, the Hubble tension can be alleviated by taking Δ N eff ≃ 0.3 induced by the light dark photon, which could be tested by CMB stage-4 and new NA64 experimental data in the near future. In addition, our light DM mass is highly testified by future data released by Belle II and CMB stage-4.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/physrevd.111.055029

Authors: Shu-Yu Ho, Jongkuk Kim, Pyungwon Ko

Institutions: Korea Institute for Advanced Study, Chung-Ang University

Language: English

Topic: Particle physics theoretical and experimental studies

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: National Research Foundation, National Research Foundation of Korea, Korea Institute for Advanced Study