Speaker
Description
Dark matter is believed to constitute approximately 25% of the total energy density of the Universe, as inferred from observations such as galactic rotation curves and the cosmic microwave background, yet it has not been directly detected. Axion-like particles (ALPs), predicted in various extensions of the Standard Model, are well-motivated dark matter candidates in the MeV–GeV mass range. EBES (Electron Beam-dump Experiment at KEK LINAC Switching Yard 3) is a new beam-dump experiment designed to search for ALPs using 4 GeV positron or 7 GeV electron beams produced at the KEK LINAC. ALPs produced through interactions of electrons or positrons with a tungsten target are detected via their decay into two photons using downstream lead-glass calorimeters. A pilot run conducted in December 2023 with a 4 GeV positron beam collected data corresponding to 1.3×10^14 positrons on target. This talk will present the results of the analysis of these data, demonstrating that EBES has sensitivity to ALPs in a parameter space complementary to other experiments.