Search for sub-eV axion-like particles in a quasi-parallel stimulated resonant photon-photon collider with "coronagraphy"

TL;DR

This study searches for sub-eV axion-like particles using a novel quasi-parallel photon-photon collider with coronagraphy to reduce background noise, setting new limits on ALP-photon coupling at specific masses.

Contribution

Developed a coronagraphy technique with an eclipse filter to suppress background photons in ALP searches, improving sensitivity in the sub-eV mass range.

Findings

No excess photons detected beyond background levels.

Extended exclusion limits for ALP-photon coupling at 0.15 eV.

Achieved the most sensitive coupling limit at this mass.

Abstract

Axion-like particles (ALPs) have been searched for with a quasi-parallel stimulated resonant photon-photon collider sensitive to the sub-eV mass range by focusing two-color near-infrared pulse lasers into a vacuum. In this work, we have developed a specialized coronagraphy to mitigate the dominant background photons from optical elements by introducing an eclipse filter. The observed number of signal-like photons was found to be consistent with residual background photons from optical elements through an additional test by degrading the focal point overlapping factor between the two lasers. We then extended the exclusion region in the relation between ALP-photon coupling, $g/M$, and the ALP mass $m$, reaching the most sensitive point $g/M = 5.45\times10^{-7}\,\mathrm{GeV^{-1}}$ at $m = 0.15\,\mathrm{eV}$ for pseudoscalar ALPs.