Search for dark matter produced in association with a Higgs boson decaying to two photons in proton-proton collisions at 13 TeV with the CMS detector

Results are presented from a search for dark matter particles produced in association with a Higgs boson decaying to two photons in proton-proton collision data collected at a center-of-mass energy of 13 TeV. The search is based on data collected in 2015 and 2016 by the CMS experiment at the CERN Large Hadron Collider. The analyzed data correspond to an integrated luminosity of 2.2 fb$^{-1}$ and 35.9 fb$^{-1}$, respectively. No significant excess over the standard model background expectation is observed. The results are used to constrain at the 95% confidence level dark matter production cross section in the context of two simplified models. A Z' mediator in a Z'-two-Higgs-doublet model with mass between 550 and 860 GeV is excluded for dark matter masses below 100 GeV. Additionally, in a baryonic Z' model, Z' masses below 574 GeV are excluded, for a dark matter mass of 1 GeV. The thesis also explores some of the challenges associated with the upgraded High-Luminosity Large Hadron Collider. One important challenge will be integrating real-time charged particle track finding and reconstruction into a hardware data selection system. A proposed FPGA-based solution that reconstructs tracks within 4 $\mu$s is discussed.