Self-interacting O(N) scalar dark matter multiplet in a Higgs-portal model with a light scalar mediator
Abstract
We investigate self-interacting dark matter in an O(N)-symmetric real scalar multiplet model with Higgs-portal interactions involving the Standard Model Higgs and a real singlet scalar. After spontaneous breaking of the singlet ℤ2 symmetry, the singlet scalar mixes with the SM Higgs boson. We focus on the regime where the resulting light scalar serves as a mediator, leading to sizable and velocity-dependent self-interactions. We impose constraints from Higgs measurements, rare B-meson decays, the dark matter relic abundance, spin-independent direct-detection searches, and scalar coupling perturbativity. We find viable parameter regions in which destructive interference between scalar-mediated scattering amplitudes suppresses the direct-detection cross section while allowing self-interactions relevant to dwarf-galaxy scales. Among these viable parameter regions, a subset also satisfies electroweak vacuum stability up to the Planck scale. Finally, we show that future long-lived-particle searches can probe part of the viable parameter space, providing complementary tests of Higgs-portal self-interacting dark matter with a light scalar mediator.
Related
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BibTeX
@misc{kim2026selfinteracting,
title = {{Self-interacting $O(N)$ scalar dark matter multiplet in a Higgs-portal model with a light scalar mediator}},
author = {U-Rae Kim and Jungil Lee and Soo-hyeon Nam},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.38050},
eprint = {2609.38050},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.38050},
}
RIS
TY - UNPB
TI - Self-interacting O(N) scalar dark matter multiplet in a Higgs-portal model with a light scalar mediator
AU - U-Rae Kim
AU - Jungil Lee
AU - Soo-hyeon Nam
PY - 2026
DA - 2026/09/29
PB - arXiv
DO - 10.48550/arxiv.2609.38050
UR - https://arxiv.org/abs/2609.38050
AB - We investigate self-interacting dark matter in an O(N)-symmetric real scalar multiplet model with Higgs-portal interactions involving the Standard Model Higgs and a real singlet scalar. After spontaneous breaking of the singlet ℤ_2 symmetry, the singlet scalar mixes with the SM Higgs boson. We focus on the regime where the resulting light scalar serves as a mediator, leading to sizable and velocity-dependent self-interactions. We impose constraints from Higgs measurements, rare B-meson decays, the dark matter relic abundance, spin-independent direct-detection searches, and scalar coupling perturbativity. We find viable parameter regions in which destructive interference between scalar-mediated scattering amplitudes suppresses the direct-detection cross section while allowing self-interactions relevant to dwarf-galaxy scales. Among these viable parameter regions, a subset also satisfies electroweak vacuum stability up to the Planck scale. Finally, we show that future long-lived-particle searches can probe part of the viable parameter space, providing complementary tests of Higgs-portal self-interacting dark matter with a light scalar mediator.
ER -