Computations That Matter 2020

The physical workshop has been rescheduled to 21 – 25 June 2021

The asymmetry between matter and antimatter remains one of the greatest puzzles in particle physics and cosmology. The Standard Model of particle physics describes all known particles and their interactions and is in perfect agreement with many experimental tests. It can, however, not explain why everything in our universe -- galaxies, planets, people -- consists of matter and not of antimatter. 

There are many different baryogenesis scenarios designed to explain this asymmetry by adding physics beyond the Standard Model. Electroweak baryogenesis  has the virtue that the required new physics already acts at the relatively low TeV (10^12 eV) energy scale. For this scenario to work the electroweak phase transition in which the elementary particles obtain their masses should proceed via the formation of bubbles (like the water-vapour transition); moreover, new sources of CP violation are needed for the particles and antiparticles in the primordial plasma to scatter differently off the bubble walls, thus sourcing the asymmetry.

State-of-the-art particle physics experiments, such as the Large Hadron Collider at CERN and precision measurements of electric dipole moments, can probe significant parts of the parameter space of new physics relevant for electroweak baryogenesis.  Entirely new and independent constraints will come from future gravitational wave observatories such as LISA, which may detect gravitational waves formed during the phase transition.

In this workshop we will address the following topics, which are crucial to get the most out of the abundance of experimental data:

- Accurate theoretical predictions. Conclusive statements about the viability of new physics models to explain the matter-antimatter asymmetry can only be drawn if theoretical predictions are accurate. Two main sources of uncertainty are the dynamics of the bubble walls in the primordial plasma,  and the dynamics of the particles scattering off the bubble walls. 

- Feasible models of new physics that are consistent with experimental constraints and satisfy the necessary conditions for electroweak baryogenesis. The most important aspects of the dynamics – the relevant cross sections, flavor effects, finite temperature corrections – will be model-dependent.

In summary, the proposed workshop aims to bring together researchers in the field of electroweak baryogenesis in a time when experimental efforts are progressing rapidly. Our hope is to create an intellectually stimulating climate that will result in progress toward understanding the origin of the cosmic matter-antimatter asymmetry. In particular, this workshop will be considered a success if we identify the major theoretical challenges and determine the steps towards improved models and predictions, and when new scientific collaborations are initiated to work out the details.