Journal article

Scalar dark matter explanation of the excess in the Belle II B → K invisible measurement

XG He, XD Ma, MA Schmidt, G Valencia, RR Volkas

Journal of High Energy Physics (JHEP) | SpringerOpen | Published : 2024

Abstract

Recently Belle II reported the first measurement of B+ → K+ + invisible(inv), which is 2.7σ above the standard model (SM) prediction. If confirmed, this calls for new physics beyond SM. In the SM, the invisible particles are neutrino-anti-neutrino pairs. There are more possibilities when going beyond the SM. In this work, we focus on decays to dark matter (DM) and show that the B → K + inv excess from Belle II and DM relic density can be simultaneously explained in a simple extension of the SM. The model introduces a real scalar singlet ϕ acting as a DM candidate, and two heavy vector-like quarks Q, D with the same quantum numbers as the SM left-handed quark doublet and right-handed down-typ..

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University of Melbourne Researchers

Grants

Awarded by National Natural Science Foundation of China


Funding Acknowledgements

This work was supported in part by Australian Research Council Discovery Project DP200101470 and in part by the Australian Research Council Centre of Excellence for Dark Matter Particle Physics (CDM, CE200100008). This work was also supported in part by Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education, and Shanghai Key Laboratory for Particle Physics and Cosmology (Grant No. 15DZ2272100) and in part by the NSFC (Grant Nos. 12375088, 12090064, and 12090060), and by the Guangdong Major Project of Basic and Applied Basic Research (Grant No.2020B0301030008) and by the NSFC (Grant No. NSFC-12305110). XDM would like to thank Jin-Han Liang and Hao-Lin Wang for useful discussions about the Migdal effect. RRV thanks Peter Cox for a helpful discussion.