Detecting the invisible universe with neutrinos and dark matter

Abstract

Recent work in astrophysics has show that most of the matter in the universe is non-luminous. This work investigates two searches for non-luminous matter: hot dark matter formed from cosmic relic neutrinos from the Big Bang, and directional detection of cold dark matter. The cosmic neutrino background is investigated through the KATRIN experiment, using neutrino capture on tritium to search for a signal. A sensitivity at KATRIN of about 10⁴ events per year, or a local overdensity of relic neutrinos of about 3 x 10⁹ is found. Directional detection of cold dark matter provides a unique way to distinguish a dark matter signal from terrestrial backgrounds, using the expected direction of a dark matter wind based on astrophysical parameters. This work presents a new technique for directional dark matter detection--a drift chamber readout using a CCD camera. The backgrounds of this detector are investigated and enumerated, and a dark matter search sets a limit at mX =100 GeV of 3.7 x 10?³³ cm².