A vast portion of the Universe is predicted to consist of an as-of-yet undetected, non-luminous form of matter, known as dark matter. Evidence of its existence has been corroborated by various astrophysical observations at many cosmological scales, and its relative abundance has been determined. However, knowledge of its nature and non-gravitational interactions is entirely lacking. Nonetheless, the predicted particle nature of dark matter allows for multiple complementary methods of its detection. This work presents a search for dark matter produced in association with a top quark pair performed using the data recorded by the CMS detector at the LHC in Geneva, Switzerland during 2016. The collision center-of-mass energy of the dataset in question is 13 TeV, and the integrated luminosity of the dataset corresponds to 35.9/fb. The analysis performed considers only the dilepton decay of top quark pairs. The results are interpreted using simplified models of dark matter and are compared to corresponding results from direct detection experiments. While the work does not provide evidence of the production of dark matter in association with a top quark pair in the dilepton final state from proton-proton collisions, it sets important constraints on the properties of dark matter.

Last modified

• 10/08/2019

Creator

• Stanislava Sevova

DOI

• https://doi.org/10.21985/n2-83x9-vq61

Subject

• Physics and Astronomy

Keyword

• Particle physics

Date created

• 2018-01-01

Resource type

• Dissertation

Rights statement

• In Copyright