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

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...

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Main Authors: Xiao-Gang He, Xiao-Dong Ma, Michael A. Schmidt, German Valencia, Raymond R. Volkas
Format: Article
Language:English
Published: SpringerOpen 2024-07-01
Series:Journal of High Energy Physics
Subjects:
Online Access:https://doi.org/10.1007/JHEP07(2024)168
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author Xiao-Gang He
Xiao-Dong Ma
Michael A. Schmidt
German Valencia
Raymond R. Volkas
author_facet Xiao-Gang He
Xiao-Dong Ma
Michael A. Schmidt
German Valencia
Raymond R. Volkas
author_sort Xiao-Gang He
collection DOAJ
description 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-type quark singlet, respectively. All these new particles are odd under a ℤ2 symmetry while the SM particles are even. The model can successfully explain the Belle II anomaly and DM relic density for TeV-scale heavy quarks with hierarchical Yukawa couplings involving b and s quarks. At the same time, it can easily satisfy other flavour physics constraints. Direct detection searches utilizing the Migdal effect constrain some of the parameter space.
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spelling doaj-art-312fbe80b3ea4e7a930b5ea2d4f04d9e2025-08-20T02:11:18ZengSpringerOpenJournal of High Energy Physics1029-84792024-07-012024711910.1007/JHEP07(2024)168Scalar dark matter explanation of the excess in the Belle II B + → K ++ invisible measurementXiao-Gang He0Xiao-Dong Ma1Michael A. Schmidt2German Valencia3Raymond R. Volkas4Tsung-Dao Lee Institute, and School of Physics and Astronomy, Shanghai Jiao Tong UniversityKey Laboratory of Atomic and Subatomic Structure and Quantum Control (MOE), Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter, Institute of Quantum Matter, South China Normal UniversitySydney Consortium for Particle Physics and Cosmology, School of Physics, The University of New South WalesSchool of Physics and Astronomy, Monash UniversityARC Centre of Excellence for Dark Matter Particle Physics, School of Physics, The University of MelbourneAbstract 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-type quark singlet, respectively. All these new particles are odd under a ℤ2 symmetry while the SM particles are even. The model can successfully explain the Belle II anomaly and DM relic density for TeV-scale heavy quarks with hierarchical Yukawa couplings involving b and s quarks. At the same time, it can easily satisfy other flavour physics constraints. Direct detection searches utilizing the Migdal effect constrain some of the parameter space.https://doi.org/10.1007/JHEP07(2024)168Models for Dark MatterRare DecaysVector-Like Fermions
spellingShingle Xiao-Gang He
Xiao-Dong Ma
Michael A. Schmidt
German Valencia
Raymond R. Volkas
Scalar dark matter explanation of the excess in the Belle II B + → K ++ invisible measurement
Journal of High Energy Physics
Models for Dark Matter
Rare Decays
Vector-Like Fermions
title Scalar dark matter explanation of the excess in the Belle II B + → K ++ invisible measurement
title_full Scalar dark matter explanation of the excess in the Belle II B + → K ++ invisible measurement
title_fullStr Scalar dark matter explanation of the excess in the Belle II B + → K ++ invisible measurement
title_full_unstemmed Scalar dark matter explanation of the excess in the Belle II B + → K ++ invisible measurement
title_short Scalar dark matter explanation of the excess in the Belle II B + → K ++ invisible measurement
title_sort scalar dark matter explanation of the excess in the belle ii b k invisible measurement
topic Models for Dark Matter
Rare Decays
Vector-Like Fermions
url https://doi.org/10.1007/JHEP07(2024)168
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