Comprehensive constraints on ALP couplings from future $$e^+e^-$$ colliders, muon $$g-2$$, thermal dark matter and Higgs measurements

Abstract In this article, we present projected 95% C.L. limits on axion-like particle (ALP) couplings from ALP production at a future $$e^+e^-$$ e + e - collider operating at $$\sqrt{s} = 250~\text {GeV}$$ s = 250 GeV with integrated luminosity $$L = 0.5~\text {ab}^{-1}$$ L = 0.5 ab - 1 . We constrain the effective couplings $$g_{\gamma \gamma }$$ g γ γ , $$g_{Z\gamma }$$ g Z γ , $$g_{ZZ}$$ g ZZ , and $$g_{WW}$$ g WW over the ALP mass range $$20~\text {GeV} \le m_a \le 100~\text {GeV}$$ 20 GeV ≤ m a ≤ 100 GeV , finding projected bounds at the level of $$\mathcal {O}(10^{-1})~\text {TeV}^{-1}$$ O ( 10 - 1 ) TeV - 1 for $$g_{\gamma \gamma }/f_a$$ g γ γ / f a . Given that the latest muon anomalous magnetic moment measurement ( $$\Delta a_\mu $$ Δ a μ ) shows no statistically significant deviation from the Standard Model prediction, we reinterpret the ALP contributions to $$\De