1. Special UCLA High Energy & Astro-Particle (HEAP) Seminar
“Direct detection of dark matter with liquid argon” Presented by Quentin Riffard APC, Paris Diderot University
A large number of astrophysical and cosmological observations at different scales supports the existence of a cold dark matter component in the Universe. At the Universe scale, this component is uniformly distributed and represents roughly 26% of the total mass-energy density of the Universe. The Weakly Interacting Massive Particle (WIMP), a generic particle, is one of the leading dark matter particle candidates: a massive particle interacting only through weak and gravitational interactions. This candidate is supported by the so-called "WIMP miracle" and could also be supported in particle physics by supersymmetric models. At the Milky Way scale, dark matter forms a static halo surrounding our galaxy. The relative motion of the solar system through the dark halo produces a flux of WIMP on Earth. Through the weak interaction, WIMP could interact with ordinary matter producing nuclear recoils (NR) by elastic scattering. In the last two decades, a large experimental effort has been deployed by international collaborations in order to probe a direct detection of NR from WIMP-nucleus interactions. In this experimental context, multi-tone noble liquid TPC are good candidate for the dark matter searches. The DarkSide program is a step approach program aiming to build a large TPC filled with liquid argon (LAr). The first part of this presentation focuses on the potential of LAr as a target for dark matter searches, on the latest results from the DS-50 detector and the perspectives of the DarkSide program: the DS-20k detector.
For a complete understanding of LAr data, the characterisation of several parameters is fundamental such as the scintillation efficiency for NR and the pulse-shape parameter for the NR/ER discrimination is fundamental. In order to improve the knowledge on these parameters, the ARIS collaboration built a small LAr double-phase TPC. A first data taking with mono chromatic neutrons was performed in Orsay (France) in last October.
The second part of this presentation presents a status of the ARIS data analysis and a discussion of the strategy to extract the parameters.
Location: Knudsen 4-134
Date: Thursday, March 16th
Time: 3:00pm
Refreshments at 2:45pm