Top-up financing of Marie Curie from UiS

The observed asymmetry between matter and antimatter in the Universe is direct evidence that the Standard Model of particle physics, recently completed through the discovery of the Higgs boson, does not account for all (non-gravitational) physical phenome na. Although all the ingredients required to explain the asymmetry from fundamental interactions are present within the Standard Model, a comprehensive effort to reproduce the observed magnitude has sofar failed. In particular, the process by which the as ymmetry is created must be strongly out of thermal equilibrium, and this cannot be provided by the electroweak phase transition, as was originally expected. This follows directly from the value of the Higgs boson mass, observed to be 125-126 GeV at the LH C at CERN, and was established in a seminal paper by Kajantie et al. (1996). The natural next step is to investigate what minimal extensions of the Standard Model can lead to a strong electroweak transition; what is the transition temperature and dynamics of the transition; and how do the resulting constraints on these theoretical extensions compare with the steadily improving experimental constraints from collider experiments. I propose to use state-of-the-art numerical lattice simulations to answer thes e questions. Because the computation involves non-perturbative and/or out-of-equilibrium phenomena, analytic methods can only take us so far. Complementing known results with numerics will allow me to establish whether a number of extension of the Standar d Model may account for the observed asymmetry, and what predictions this infers for collider experiments; and I will simulate the dynamics of a strongly first order phase transition, the nucleation of vacuum bubbles and interaction with a thermal plasma.