Searching for long-lived particles from stopped pions and muons at the CiADS-BDE

TL;DR

The paper evaluates the potential of the CiADS-BDE beam-dump experiment to detect various long-lived particles from pion and muon decays, extending the search for new physics beyond current limits.

Contribution

It demonstrates the experiment's capability to explore new parameter spaces for multiple models predicting long-lived particles, including heavy neutral leptons and axion-like particles.

Findings

Probes new parameter regions beyond existing bounds.

Sensitive to long-lived particles from pion and muon decays.

Applicable to models like heavy neutral leptons, axion-like particles, and light binos.

Abstract

The CiADS-BDE is a beam-dump experiment recently proposed for searching for light, long-lived particles (LLPs) at China initiative Accelerator Driven System. Primarily thanks to the large numbers of protons on target at the experiment, it has been shown to be sensitive to large, unique regions of the parameter space of dark photon, with a small detector volume of $\mathcal{O}(0.01\text{--}1)$ m$^3$. Here, we explore the search prospect of the CiADS-BDE for a series of new-physic models predicting LLPs that could emanate from decays at rest of charged pions and muons at the facility, namely, heavy neutral leptons, axionlike particles, and light binos in the R-parity-violating supersymmetry. For these benchmark models, we find that the CiADS-BDE can also probe vast parameter regions beyond the existing bounds.