Searching for Light–Dark Matter with Positron Beams

Abstract

In the present contribution, we present preliminary ideas on the advantage of using positron beams on fixed target in searching for the $A'$. In particular, we will discuss $A'$ production mechanisms, accessible only at positron machines, which might offer enhanced cross sections compared to the commonly used $A'$-strahlung. Recent studies show that the inclusion of such processes in the reinterpretation of old beam dump experiments results in significantly more stringent exclusion limits. Finally, we will discuss the peculiar case of searches for candidates with defined mass, using as a benchmark case the $^8Be$ 16.7 MeV X-Boson.