Theoretical Background

This chapter provides a concise overview of key topics in contemporary particle physics. It begins with a brief discussion of the history of particle physics, tracing the development of key concepts and discoveries that have shaped the current understanding of the field. This is followed by an overview of the Standard Model of particle physics, outlining its fundamental particles and interactions. Next, the chapter delves into the evidence for dark matter, discussing current experimental efforts aimed at its detection. Finally, the chapter concludes with a brief overview of the Higgs portal models, which propose interactions between the Standard Model Higgs boson and dark matter. The chapter explains how such interactions can be observed as invisible decays of the Higgs boson (commonly denoted as \({\text{H} \rightarrow \text{inv.}} \) ) in particle detectors.