Search for sub-eV axion-like resonance states via stimulated quasi-parallel laser collisions with the parameterization including fully asymmetric collisional geometry

TL;DR

This study searches for sub-eV axion-like particles by using stimulated photon-photon scattering in asymmetric laser collision geometries, setting new experimental bounds on their coupling and mass.

Contribution

It introduces a comprehensive parameterization for asymmetric collisional geometries in laser-based axion searches, improving upon previous symmetric assumptions.

Findings

No significant axion-like resonance signals detected.

Established upper bounds on axion-like particle coupling in the sub-eV mass range.

Enhanced experimental framework for future axion-like particle searches.

Abstract

We have searched for axion-like resonance states by colliding optical photons in a focused laser field (creation beam) by adding another laser field (inducing beam) for stimulation of the resonance decays, where frequency-converted signal photons can be created as a result of stimulated photon-photon scattering via exchanges of axion-like resonances. A quasi-parallel collision system (QPS) in such a focused field allows access to the sub-eV mass range of resonance particles. In past searches in QPS, for simplicity, we interpreted the scattering rate based on an analytically calculable symmetric collision geometry in both incident angles and incident energies by partially implementing the asymmetric nature to meet the actual experimental conditions. In this paper, we present new search results based on a complete parameterization including fully asymmetric collisional geometries. In particular, we combined a linearly polarized creation laser and a circularly polarized inducing laser to match the new parameterization. A 0.10 mJ / 31 fs Ti:sapphire laser pulse and a 0.20 mJ / 9 ns Nd:YAG laser pulse were spatiotemporally synchronized by sharing a common optical axis and focused into the vacuum system. Under a condition in which atomic background processes were completely negligible, no significant scattering signal was observed at the vacuum pressure of $2.6 \times 10^{-5}$ Pa, thereby providing upper bounds on the coupling-mass relation by assuming exchanges of scalar and pseudoscalar fields at a 95 % confidence level in the sub-eV mass range.