POKER: POsitron resonant annihilation into darK mattER
Light dark matter is the new compelling hypothesis that identifies dark matter with new sub-GeV “Hidden Sector” states, neutral under Standard Model interactions and interfacing with our world through a new force. Accelerator-based searches at the intensity frontier are uniquely suited to explore it. However, current and planned efforts are either limited by the low sensitivity or the high backgrounds. This calls for a major breakthrough in the field.
The goal of POKER is to establish and demonstrate a new approach to search for light dark matter, based on a missing energy measurement with a positron-beam, active thick-target setup.
The new technique, based on light dark matter production through positron annihilation on atomic electrons, is characterized by a larger signal yield compared to previously explored reactions, and by a unique signal signature resulting from the underlying reaction dynamics: a peak in the missing energy distribution.
The final objective of the project, approved as a 1.5 M€ ERC Starting Grant for 2020-2025, is to perform a pilot run with the 100 GeV positron beam available at the H4 beamline at CERN, to demonstrate the technique by exploring a so-far unknown territory in the Hidden Sector parameters space.
In this seminar, after a brief introduction the Hidden Sector physics case, I’ll first discuss the potential of accelerator-based light dark matter efforts. I’ll then present the POKER experiment, focusing on the active thick target – the key element of the project. I’ll finally show the sensitivity of POKER to different Light Dark Matter scenarios.