We propose DREAMuS, a fixed-target experiment at the High Intensity Heavy-Ion Accelerator Facility (HIAF), to search for muon-philic dark matter mediated by light flavor-violating bosons. DREAMuS is designed to probe the parameter space of a muon-philic dark matter (DM) mediated by a light flavor-violating boson, specifically a vector Z′ (or a scalar ϕ) which is produced in muon-nucleus interactions and decays into dark matter particles with a distinctive detector signature. Precision tracking and time-of-flight measurements are used to suppress the Standard Model backgrounds. We find that DREAMuS can achieve competitive sensitivity in the GeV-scale muon-philic dark matter parameter space, reaching sensitivity to couplings at the 10−4, especially in the few-hundred-MeV region.In addition to a μ− run, we highlight the potential of a complementary μ+ beam option, further improving sensitivity to dark matter below 200 MeV by an order of magnitude.
@article{arxiv.2604.10257,
title = {DREAMuS: Dark matter REsearch with Advanced Muon Source},
author = {Xiang Chen and Zejia Lu and Liangwen Chen and Jun Gao and Shao-Feng Ge and Zhanxu Hao and Yang Hu and Bingzhi Li and Cen Mo and Zhiyu Sun and Huayang Wang and Chonghao Wu and Yu Xu and Xueheng Zhang and Yulei Zhang and Liang Li},
journal= {arXiv preprint arXiv:2604.10257},
year = {2026}
}