Particle Theory Seminar - Was There an Electroweak Phase Transition?, Michael Ramsey-Musolf, UMass Amherst

Determining the thermal history of electroweak symmetry breaking (EWSB) is a key task for particle physics and cosmology. In the Standard Model, EWSB occurs via a crossover transition. In many scenarios for beyond the Standard Model (BSM) physics, however, the nature of the transition and pattern can differ, with important implications for baryogenesis and gravitational wave generation. I give generic arguments for why any BSM physics that leads to such an alternate history will be accessible at the LHC and next generation colliders. I also discuss recent developments in effective field theory and nonperturbative computations that are essential for a robust confrontation of theory with experiment.