B + → K + ν ν ¯ excess and DM semi-annihilation
Abstract
In 2023, the Belle II Collaboration announced the observation of the B + → K + ν ν ¯ decay channel for the first time. This decay channel provides a clean signal with high precision in theoretical calculations. However, we encounter a 2.8 σ deviation from the Standard Model prediction. To resolve this excess, we study a scalar dark matter model with local discrete Z 3 symmetry. Assuming dark U ( 1 ) X ≡ U ( 1 ) L μ − L τ symmetry, this U ( 1 ) L μ − L τ symmetry is spontaneously broken into local discrete Z 3 by nonzero vacuum expectation value of dark Higgs boson. Considering a dark Higgs mass is 2 GeV, we can explain the recent Br ( B + → K + ν ν ¯ ) excess reported from the Belle II Collaboration and relic abundance at the same time.
Fields of Study & Subjects
Boron and Carbon Nanomaterials Research
Boron Compounds in Chemistry
Cold Atom Physics and Bose-Einstein Condensates
Publication details
- Journal / source
- Physical review. D/Physical review. D.
- Publisher
- American Physical Society (APS)
- Volume
- 113
- Issue
- 7
- Publication date
- 5 March 2026
- Language
- EN