# Searching for axionlike particle at future $ep$ colliders

## TL;DR

This paper investigates the potential of future electron-proton colliders to detect axionlike particles through specific subprocesses, providing competitive sensitivity to their coupling parameters in a broad mass range.

## Contribution

It presents a novel analysis of ALP detection prospects at $ep$ colliders, extending the search sensitivity to higher mass ranges and comparing it with existing bounds.

## Key findings

- Future $ep$ colliders can effectively probe ALP-photon couplings.
- Sensitivity to ALP mass range from 10 GeV to 3 TeV.
- Bounds are competitive with current collider constraints.

## Abstract

We explore the possibility of searching for axionlike particle (ALP) by $ep$ collisions via the subprocess $e^{-}\gamma \rightarrow e^{-}a \rightarrow e^{-}\gamma\gamma$. Sensitivities to the effective ALP-photon coupling $g_{a\gamma\gamma}$ for its mass in the range of 10 GeV $< M_{a}< 3$ TeV are obtained for the LHeC and its high-energy upgrade, FCC-eh. Comparing to existing bounds on the ALP free parameters, we find that the bounds given by $ep$ colliders are competitive and complementary to other colliders.