Seminarium Fizyki Wielkich Energii

As any e+e- scattering process can be accompanied by a hard photon emission from the initial state radiation, the analysis of the energy spectrum and angular distributions of those photons can be used to search for hard processes with an invisible final state. Thus high energy e+e- colliders offer a unique possibility for the most general search ofdark matter (DM) based on the mono-photon signature. Production of DM particles at the International Linear Collider (ILC) and Compact Linear Collider (CLIC) experiments was studied for scenarios with a light mediator exchange. Limits on the production cross section and mediator couplings were set in a simplified DM model as a function of the mediator mass and width based on the expected two-dimensional distributions of the reconstructed mono-photon events. Systematic uncertainties were studied in details as well as the impact of the beam polarisation.