Search for photoproduction of axion-like particles at GlueX

TL;DR

This paper reports a search for axion-like particles produced in photon-proton collisions at GlueX, setting new exclusion limits on their coupling strength in specific mass ranges, with no evidence of detection.

Contribution

First search for axion-like particles at GlueX focusing on $a$-gluon coupling, providing the most stringent limits to date in the studied mass ranges.

Findings

No evidence for axion-like particles was found.

Established new exclusion limits on $a$-gluon coupling.

Covered mass ranges 180-480 MeV and 600-720 MeV.

Abstract

We present a search for axion-like particles, $a$, produced in photon-proton collisions at a center-of-mass energy of approximately 4 GeV, focusing on the scenario where the $a$-gluon coupling is dominant. The search uses $a\to\gamma\gamma$ and $a\to\pi^+\pi^-\pi^0$ decays, and a data sample corresponding to an integrated luminosity of 168 pb$^{-1}$ collected with the GlueX detector. The search for $a\to\gamma\gamma$ decays is performed in the mass range of $180 < m_a < 480$ MeV, while the search for $a\to\pi^+\pi^-\pi^0$ decays explores the $600 < m_a < 720$ MeV region. No evidence for a signal is found, and 90% confidence-level exclusion limits are placed on the $a$-gluon coupling strength. These constraints are the most stringent to date over much of the mass ranges considered.