Inelastic dark matter models that have two dark matter particles and a massive dark photon can reproduce the observed relic dark matter density without violating cosmological limits. The mass splitting between the two dark matter particles χ1 and χ2, with m(χ2)>m(χ1), is induced by a dark Higgs field and a corresponding dark Higgs boson h′. We present a search for dark matter in events with two vertices, at least one of which must be displaced from the interaction region, and missing energy. Using a 365 fb-1 data sample collected at Belle II, which operates at the SuperKEKB e+e- collider, we observe no evidence for a signal. We set upper limits on the product of the production cross section σ(e+e-→h′χ1χ2), and the product of branching fractions B(χ2→χ1e+e-)×B(h′→x+x-), where x+x- indicates μ+μ-,π+π-, or K+K-, as functions of h′ mass and lifetime at the level of 10-1 fb. We set model-dependent upper limits on the dark Higgs mixing angle at the level of 10-5 and on the dark photon kinetic mixing parameter at the level of 10-3. This is the first search for dark Higgs bosons in association with inelastic dark matter.

Adachi, I., Aggarwal, L., Ahmed, H., Aihara, H., Akopov, N., Alghamdi, S., et al. (2025). Search for a Dark Higgs Boson Produced in Association with Inelastic Dark Matter at the Belle II Experiment. PHYSICAL REVIEW LETTERS, 135(13), 131801-1-131801-10 [10.1103/37w5-glpp].

Search for a Dark Higgs Boson Produced in Association with Inelastic Dark Matter at the Belle II Experiment

Di Canto A.;
2025

Abstract

Inelastic dark matter models that have two dark matter particles and a massive dark photon can reproduce the observed relic dark matter density without violating cosmological limits. The mass splitting between the two dark matter particles χ1 and χ2, with m(χ2)>m(χ1), is induced by a dark Higgs field and a corresponding dark Higgs boson h′. We present a search for dark matter in events with two vertices, at least one of which must be displaced from the interaction region, and missing energy. Using a 365 fb-1 data sample collected at Belle II, which operates at the SuperKEKB e+e- collider, we observe no evidence for a signal. We set upper limits on the product of the production cross section σ(e+e-→h′χ1χ2), and the product of branching fractions B(χ2→χ1e+e-)×B(h′→x+x-), where x+x- indicates μ+μ-,π+π-, or K+K-, as functions of h′ mass and lifetime at the level of 10-1 fb. We set model-dependent upper limits on the dark Higgs mixing angle at the level of 10-5 and on the dark photon kinetic mixing parameter at the level of 10-3. This is the first search for dark Higgs bosons in association with inelastic dark matter.
2025
Adachi, I., Aggarwal, L., Ahmed, H., Aihara, H., Akopov, N., Alghamdi, S., et al. (2025). Search for a Dark Higgs Boson Produced in Association with Inelastic Dark Matter at the Belle II Experiment. PHYSICAL REVIEW LETTERS, 135(13), 131801-1-131801-10 [10.1103/37w5-glpp].
Adachi, I.; Aggarwal, L.; Ahmed, H.; Aihara, H.; Akopov, N.; Alghamdi, S.; Alhakami, M.; Aloisio, A.; Althubiti, N.; Amos, K.; Angelsmark, M.; Anh Ky,...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1084190
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