Speaker
Description
Light dark matter (LDM), with masses in the MeV to GeV range, is theoretically well motivated but remarkably unexplored. The JLab Beam Dump eXperiment (BDX) is an approved proposal to collect up to 10^22 electrons-on-target (EOT) at 11 GeV during 285 days to search for LDM using a segmented CsI(Tl) scintillator detector placed downstream of the Hall A beam-dump at Jefferson Lab. This experiment will be sensitive to elastic DM-electron and to inelastic DM scattering at the level of several counts per year, probing the limit of the neutrino irreducible background. In the case of no signal, its sensitivity will allow exclusion limits to be extended by one to two orders of magnitude in the parameter space of dark-matter coupling versus mass.
In this talk, we will present the limits on LDM obtained with a pilot experiment (BDX-MINI), which accumulated 2.56 x 10^21 EOT during six months of running with the CEBAF 2.176 GeV electron beam incident on the Hall A beam dump. A blind data analysis based on a maximum-likelihood approach allowed this pilot experiment to probe the edges of existing limits on LDM, which demonstrates the discovery potential of the next generation beam dump experiment planned at intense electron beam facilities.
| speaker affiliation | Jefferson Lab and the College of William and Mary |
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