Thursday, November 5, 2020, 16:00
online only
Paolo Crivelli, ETHZ
Abstract:
NA64 is a fixed target experiment at the CERN SPS aiming at a sensitive
search for hidden sectors. I will present the experiment and our latest
results on the search for a new sub-GeV vector gauge boson (A') mediated
dark matter (χ) production. The A', called dark photon, could be
generated in the reaction e- Z → e- ZA' of
100 GeV electrons dumped against an active target which is followed by
the prompt invisible decay A' → χ χ. The experimental
signature of this process would be a clean event with an isolated
electron and large missing energy in the detector. This allows us to set
new limits on the γ-A' mixing strength and constrain some
parameter space for the most interesting light dark matter models.
Results on the search for the visible A' →
e+e- decays, as well as X →
e+e- decay of a new 17 MeV X boson, which could
explain a recently observed anomaly in the 8Be transitions
and a search for axion-like particles will be also discussed. I will
conclude with the future prospects of the experiment which will resume
data taking in 2021 after the CERN long shutdown.