Light top-flavoured dark matter in dark SMEFT: one-loop matching and phenomenology
Abstract
We study light top-flavoured dark matter (DM) below the electroweak (EW) scale within the dark Standard Model effective field theory (DSMEFT). We perform the one-loop matching of the DSMEFT onto the dark low-energy effective field theory (DLEFT) at the EW scale for all relevant operators that couple scalar, fermionic or vector DM, as well as axion-like particles, exclusively to third-generation quarks. After QCD evolution to the relevant low-energy scales, we match the DLEFT onto the non-relativistic EFT for DM-nucleus scattering. This EFT chain provides a unified framework for phenomenological studies of rare B- and K-meson decays with missing energy, direct and indirect detection, and the thermal relic abundance. Interpreting the Belle II excess in B+→ K+νν̅ as a decay into DM, we find that only the DSMEFT operators contributing at tree level can accommodate it with O(1) couplings for a new-physics scale of 1 TeV. The decay B0→ K*0+inv provides the strongest constraint over large portions of the Belle II-favoured parameter space, while K+→π++inv can dominate at low and Bs→inv, B+→π++inv and Υ(1S)→inv become important at high DM masses, respectively. Direct-detection searches by CRESST-III and DarkSide-50 are competitive for operators involving scalar quark currents and, depending on the operator, exclude the Belle~II-favoured band for mDM≳1-2 GeV. We also perform detailed analyses of the thermal relic abundance and the indirect-detection constraints from the CMB and Fermi-LAT.
Related
- Anomalous Dimensions, Matching, and Phenomenology of Dirac Fermionic Dark Matter Effective Interactions
- Matching ν2HDM onto νSMEFT up to one-loop accuracy
- Benchmark Dark SMEFT Scenarios from the Interplay of Flavor Physics and Dark Matter Searches
- Probing Leptophilic Scalar Dark Matter with SMEFT and Direct Detection
- Flavor phenomenology of light dark particles
BibTeX
@misc{gao2026light,
title = {{Light top-flavoured dark matter in dark SMEFT: one-loop matching and phenomenology}},
author = {Meng-Chao Gao and Xin-Qiang Li and Ya-Dong Yang and Xing-Bo Yuan and Xin Zhang},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.34880},
eprint = {2610.34880},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.34880},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Light top-flavoured dark matter in dark SMEFT: one-loop matching and phenomenology
AU - Meng-Chao Gao
AU - Xin-Qiang Li
AU - Ya-Dong Yang
AU - Xing-Bo Yuan
AU - Xin Zhang
PY - 2026
DA - 2026/10/26
PB - arXiv
DO - 10.48550/arxiv.2610.34880
UR - https://arxiv.org/abs/2610.34880
AB - We study light top-flavoured dark matter (DM) below the electroweak (EW) scale within the dark Standard Model effective field theory (DSMEFT). We perform the one-loop matching of the DSMEFT onto the dark low-energy effective field theory (DLEFT) at the EW scale for all relevant operators that couple scalar, fermionic or vector DM, as well as axion-like particles, exclusively to third-generation quarks. After QCD evolution to the relevant low-energy scales, we match the DLEFT onto the non-relativistic EFT for DM-nucleus scattering. This EFT chain provides a unified framework for phenomenological studies of rare B- and K-meson decays with missing energy, direct and indirect detection, and the thermal relic abundance. Interpreting the Belle II excess in B^+→ K^+νν̅ as a decay into DM, we find that only the DSMEFT operators contributing at tree level can accommodate it with O(1) couplings for a new-physics scale of 1 TeV. The decay B^0→ K^*0+inv provides the strongest constraint over large portions of the Belle II-favoured parameter space, while K^+→π^++inv can dominate at low and B_s→inv, B^+→π^++inv and Υ(1S)→inv become important at high DM masses, respectively. Direct-detection searches by CRESST-III and DarkSide-50 are competitive for operators involving scalar quark currents and, depending on the operator, exclude the Belle~II-favoured band for m_DM≳1-2 GeV. We also perform detailed analyses of the thermal relic abundance and the indirect-detection constraints from the CMB and Fermi-LAT.
ER -