Search for Axion-like particles at an electron-positron accelerator
Mathias Heiles (JGU Mainz)

Beside the origin of the axion from the solution for the strong CP problem proposed by Peccin and Quinn, an axion-like particle (ALP) arises from various theories beyond the Standard Model (SM). The interaction of the pseudoscalar, which is a gauge singlet under the SM gauge group, with the SM particles will be described by means of an effective Field Theory (EFT). After a short introduction, the decay of ALPs into SM particles is considered. Following that, three production processes of an ALP together with a Higgs boson, a photon and a Z boson at an e+e- collider will be discussed. These processes probe the parameter space of the ALP couplings to SM fi elds. In addition, the two future colliders FCC-ee and ILC will be compared regarding their investigatable region in the parameter space of the ALP. Furthermore, the production process of an ALP together with a pair of muons is discussed, which gives constraints on the ALP parameter space by means of a search of BaBar for dark Z-bosons.