Schroeder, Neil2025-01-282025-01-282024-07https://hdl.handle.net/11299/269599University of Minnesota Ph.D. dissertation. July 2024. Major: Physics. Advisor: Roger Rusack. 1 computer file (PDF); x, 138 pages.A measurement of the mass of the Higgs boson has been performed in the diphoton decay channel. This analysis is based on 138 fb⁻¹ of pp collision data collected in 2016-2018 with the CMS detector at the LHC at a center-of-mass energy of 13 TeV. The mass is measured to be 𝐦𝐇 = 125.574 ± 0.088 (stat.) ± 0.121 (syst.) GeV. This thesis summarizes the strategy of this measurement with emphasis on the methods employed to mitigate and quantify the main sources of systematic uncertainty.enCERNCMSdiphotonhiggsmassmeasurementThesis or Dissertation