Abstract:
The discovery of the Higgs boson at the Large Hadron Collider completed the Standard Model, but many fundamental open questions remain. One question is particularly simple: how could the Big Bang produce the matter-dominated universe we observe without anti-matter, which should have been produced in equal parts? As the LHC switches into its High-Luminosity phase, the huge datasets the ATLAS experiment will collect can provide answers to this question, and others, by measuring the extremely rare production of pairs of Higgs bosons. Though difficult to observe, these signatures can directly measure the shape of the Higgs potential: deviations from the Standard Model's expectations could allow us to understand not just the history of the early universe that created the matter/anti-matter asymmetry, but questions like the future stability of the universe. This seminar will focus on the challenges to detecting Higgs boson pairs, and how to interpret them to understand the shape of the Higgs potential and consequences for physics beyond the Standard Model. The latest results from ATLAS’s searches in multiple channels, as well as their combinations, will be presented.