Searching for Scalar Wave Dark Matter with Levitated Magnetomechanics Sensitivity Studies for a Hypothetical Direct Detection Experiment Using Superconducting Levitating Objects

Abstract

This thesis investigates the light scalar boson, with mass between 1.24 · 10−13 and 4.14 · 10−12 eV, as a wave dark matter candidate. For such low masses, the bosons can be described as a classical wave instead of individual particles, which motivates a field description of the dark matter. The scalar boson is assumed to interact only with neutrons in a charge-neutral test object, giving it a time-dependent EP violating acceleration that can be detected in a direct detection experiment. The focus of this thesis was to develop a theoretical and statistical framework for the scalar boson by deriving this EP-violating acceleration, and applying the principle of detection to a potential experiment at Chalmers University of Technology using levitated magnetomechanics. The achievable experimental sensitivity could then be estimated for the hypothetical experiment with analytic derivations of exclusion and discovery limits for the scalar-neutron coupling constant. The purpose of the limits was to determine for which values of the coupling constant the dark matter candidate could be detected or not, and they were derived analytically with the help of a likelihood formalism utilising the so called Asimov data set. Comparing the results with a similar analysis done for the same dark matter candidate, the achievable sensitivity for the proposed magnetic levitation experiment could be concluded to be relatively high.