Theory HEP Seminar

The Electroweak Phase Transition: A Collider Target

Michael Ramsey-Musolf

University of Massachusetts Armhest

Uncovering the thermal history of electroweak symmetry breaking (EWSB) is a key challenge for particle physics and cosmology. Thee EWSB transition in a purely Standard Model universe is predicted to be of a crossover nature. However, the presence of new interactions with the Higgs boson involving sub-TeV particles could alter this history, leading to one or more first order phase transitions. The occurrence of a first order EWSB transition could provide the necessary preconditions for generation of the cosmic matter-antimatter asymmetry and lead to the production of gravitational waves. In this talk, I argue that the LHC and prospective next generation high energy colliders are poised to determine whether or not such an alternative thermal history was realized in nature.