The ALP miracle revisited

TL;DR

This paper revisits the ALP miracle scenario, analyzing the parameter space for a unified inflaton and dark matter axion-like particle, and assesses its detectability in future experiments.

Contribution

It extends previous analysis to identify the full viable parameter space and evaluates the relic density considering model uncertainties.

Findings

Preferred ALP mass range: 0.01 to 1 eV

Coupling to photons: around 10^{-11} GeV^{-1}

Detectability within reach of future experiments like IAXO and TASTE

Abstract

We revisit the ALP miracle scenario where the inflaton and dark matter are unified by a single axion-like particle (ALP). We first extend our previous analysis on the inflaton dynamics to identify the whole viable parameter space consistent with the CMB observation. Then, we evaluate the relic density of the ALP dark matter by incorporating uncertainties of the model-dependent couplings to the weak gauge bosons as well as the dissipation effect. The preferred ranges of the ALP mass and coupling to photons are found to be $0.01\lesssim m_\phi \lesssim 1$\,eV and $g_{\phi \gamma \gamma} = {\cal O}(10^{-11})$\,GeV$^{-1}$, which slightly depend on these uncertainties. Interestingly, the preferred regions are within reach of future solar axion helioscope experiments, IAXO and TASTE, and laser-based stim