Theory Vision at LHCP 2019
2019 September 05
Drawing upon the theory vision articulated at the LHC's inception, I survey the progress of the last 35 years and summarize the questions confronting particle physics in the present day. The discovery of the Higgs boson at the LHC illuminates the origin of mass but poses a host of new questions: Is the Higgs elementary, or composite? Does it interact with itself? Does it mediate a Yukawa force between fundamental particles? These are the questions of our era, and I argue that they define compelling experimental targets within reach of the HL-LHC and future Higgs factories, with answers that are profoundly interesting whether or not they agree with Standard Model predictions. Equally important is the LHC's role in exploring more speculative possibilities for physics beyond the Standard Model, from the nature of dark matter to the origin of flavor to the electroweak hierarchy problem. I emphasize the value of the hierarchy problem as an empirically-motivated strategy for looking for new physics, highlighting novel possibilities motivated by LHC null results in conventional searches. Complementing specific theoretical motivations, a host of new search strategies, signatures, hardware, and detectors will maximize the LHC's sensitivity to unforeseen new physics in the coming years. I conclude by discussing the powerful role that proposed Higgs factories can play in answering the key questions of our era, emphasizing the value of exploration in making the physics case for current and future colliders.