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Jul 26 – 30, 2021
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Blast from the past: Constraints on the dark sector from the BEBC WA66 beam dump experiment

Jul 27, 2021, 11:00 AM


Parallel session talk Searches for New Physics T10: Searches for New Physics


Mr Giacomo Marocco (University of Oxford)


We derive limits on millicharged dark states, as well as particles with electric or magnetic dipole moments, from the number of observed forward electron scattering events at the Big European Bubble Chamber in the 1982 CERN-WA-066 beam dump experiment. The dark states are produced by the 400 GeV proton beam primarily through the decays of mesons produced in the beam dump, and the lack of excess events places bounds extending up to GeV masses. These improve on bounds from all other experiments, in particular CHARM II.

First author Giacomo Marocco
Collaboration / Activity BEBC WA66 BeamDump (historical

Primary authors

Mr Giacomo Marocco (University of Oxford) Prof. Subir Sarkar (University of Oxford)

Presentation materials