We investigate the sensitivity to the effective operators describing interactions between dark matter particles and photons at future high energy e+e− colliders via the γ+\slashedE channel. Such operators could be useful to interpret the potential gamma-ray line signature observed by the Fermi-LAT. We find that these operators can be further tested at e+e− colliders by using either unpolarized or polarized beams. We also derive a general unitarity condition for 2→n processes and apply it to the dark matter production process e+e−→χχγ.
@article{arxiv.1307.5740,
title = {Detecting interactions between dark matter and photons at high energy $e^+e^-$ colliders},
author = {Zhao-Huan Yu and Qi-Shu Yan and Peng-Fei Yin},
journal= {arXiv preprint arXiv:1307.5740},
year = {2015}
}