The ATLAS Collaboration at the CERN Large Hadron Collider (LHC) is a particle physics experiment that analyzes high-energy proton-proton collisions to test the predictions of the Standard Model (SM), a theory encompassing our current understanding of the fundamental particles and interactions of the universe. In 2012, it co-discovered the Higgs boson, a particle that arises from the mechanism through which matter in the universe acquires mass. In addition to the cornerstone role that the Higgs boson plays in the SM, it is also intricately connected to many questions---such as the origin of multiple generations of matter, stability of the universe, and others---whose explanations require a more complete theory beyond the SM (BSM). Further discoveries of new states or forces that would constitute evidence of BSM phenomena, however, remain elusive within the energy reach of the LHC.

I present an avenue in which indirect searches for BSM phenomena can been conducted by deepening our understanding of the Higgs boson's properties. To this end, the most precise measurements to date of Higgs boson production cross-sections decaying into W bosons are performed. These measurements are combined with results from other decay channels and interpreted under an effective field theory to characterize the presence of BSM phenomena.