IN SEARCH OF HIDDEN SECTOR THROUGH THE MONO-PHOTON CHANNEL

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2022-12-02
Sartaş, Enfal
A growing body of experimental and observational evidence shows that Standard Model calculations account for only 5% of the mass and energy of the universe. The remainder consists of dark matter and dark energy, which have yet to be observed. The existence of dark matter, first discovered by Fritz Zwicky, suggests the presence of a hidden sector that is almost neutral under any of the forces predicted by the Standard Model. Within the framework of the portal concept, the vector portal, which brings its own additional dark gauge symmetry, is one of the proposed portals connecting the hidden sector with the Standard Model sector. Holding an additional gauge symmetry also means having an extra gauge field, hence a gauge boson. The traces of this gauge boson, namely the dark photon, are intended to be separated from the SM background in the context of this thesis. Research on the mono-photon channel is carried out within the framework of a B-L model, which is established to explore the decay and production processes of a light-dark photon (in the order of MeV-GeV), and corresponding results are obtained. First, the Lagrangian of the B-L model is created with the assistance of the FeynRules program, and therefore the models mass matrices and interaction vertices are obtained through this program. Then, a model interface is constructed employing the FeynRules program once more for the Madgraph package program that will be used to examine the production and decay channels. In addition to neutrinos, one of the possible undercover decay channels of the dark photon is the decay channel to a dark matter pair. Therefore, the missing energy in the signal of the mono-photon channel (photon + missing energy) needs to contain not only SM particles but also dark matter particles, depending on the model structure. At the final stage of the analysis, the interaction between dark matter and SM particles via the dark photon is also taken into account.

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Citation Formats
E. Sartaş, “IN SEARCH OF HIDDEN SECTOR THROUGH THE MONO-PHOTON CHANNEL,” M.S. - Master of Science, Middle East Technical University, 2022.