DFSZ Modelinde Üçlü Skaler Kuplajın Analizi

Even though the Standard Model successfully describes the fundamental particle interactions in nature (except gravity) various theoretical and experimental findings indicate that it is an incomplete theory. By extending the scalar sector, which is the most minimal part of the Standard Model, it is possible to address unresolved problems. In this thesis, we aim to solve particularly the strong CP problem by extending the Standard Model with an additional Higgs doublet and a complex scalar singlet. In the literature, this extension is referred to as the DFSZ (Dine–Fischler–Srednicki–Zhitnitsky) model. As a consequence of this extension, a new pseudo-Nambu-Goldstone boson, known as the axion emerges from the spontaneous breaking of the chiral Peccei-Quinn symmetry. The axion introduced by this model may solve the strong CP problem naturally and may also serve as a dark matter candidate. The equation determining the axion mass is derived and the phenomenological implications of the model are investigated numerically.