Investigation of the Higgs Bosons in beyond the standard model and constraining the 2HDM

In 2012, a scalar particle with similar properties to the Higgs boson predicted by the Standard Model was discovered in ATLAS and CMS experiments, so Higgs mechanism of the SM, which explains the mass gain of basic particles, has been confirmed. So far, SM has been tested many times with data obtained from particle accelerators and it has been found that SM produces very consistent results. SM is a consistent model in itself, but it is insufficient to explain all natural phenomena in the universe. In order to widen our limits in understanding the universe, beyond the Standard Model, theories have been introduced to point out new symmetries and the existence of particles. A simple extension of the SM is the Two Higgs Doublet Model (2HDM). This model is obtained by adding a second Higgs doublet to the scalar sector of the SM. Thus the 2HDM has a rich phenomenology because it predicts five scalar Higgs bosons (CP-even (h^0, H^0), CP-odd (A^0) and charged (H^±) Higgs states) and their new coupling with other particles. The aim of this study is to test the hypothesis m_(h^0)Keyword: Higgs bozonu = Higgs boson ; İki Higgs dubleti = Two Higgs doublet