Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8186565 | Physics Letters B | 2018 | 6 Pages |
Abstract
Dark photon (Aâ²) that couples to the standard model fermions via the kinetic mixing with photons and serves as a mediator of dark matter production could be observed in the high-energy electron scattering eâ+Zâeâ+Z+Aâ² off nuclei followed by the bremsstrahlung Aâ²âinvisible decay. We cross check the exact tree-level calculations of the Aâ² production cross sections by other results and implement them in the program for the full simulation of such events in the experiment NA64 at the CERN SPS . Using simulations results, we study the missing energy signature for the Aâ²âinvisible decay that allows to probe the γâAâ² mixing strength in a wide, from sub-MeV to sub-GeV, Aâ² mass range. We refine and expand our earlier studies of this signature by including corrections to the previously used calculations based on the improved Weizsaker-Williams (IWW) approximation, which turn out to be significant. We find that the commonly used IWW approach can lead to substantial overestimation of the sensitivity to Aâ² in fixed target experiments. The possibility of future searches with high-energy electron beams and their sensitivity to Aâ² are briefly discussed.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Nuclear and High Energy Physics
Authors
S.N. Gninenko, D.V. Kirpichnikov, M.M. Kirsanov, N.V. Krasnikov,