Electroweak precision test of axion-like particles

We study the contributions of an axion-like particle to electroweak precision observables. The is assumed couple with standard model gauge bosons. provide formulae valid for any mass particle. It found that effects arise not only via oblique $S$ and $U$ parameters but also radiative corrections couplings. Besides, decay $Z\to a\gamma$ affects total width $Z$ boson. All those are considered simultaneously in global fit analysis Also, we discuss recent CDF result $W$-boson measurement. Since tightly constrained by flavor collider constraints, it discrepancy from prediction solved when heavier than 500 GeV its coupling di-photon suppressed.