Discovery Scenarios

A Shortage of Antimatter

The dominance of matter over antimatter in the universe remains a mystery. The family of Higgs particles may have deep connections with this question.

In the instant after the Big Bang, physicists believe that the universe was too hot for the Higgs to do its job of dispensing mass. A short time later, the universe cooled enough for the Higgs to go to work. Within the known laws of physics, this explanation provides almost, but not quite, enough ingredients to produce an imbalance of matter over antimatter. What appear to be missing are a stronger source for this matter-antimatter imbalance and some additional interactions, such as interactions of the Higgs with other Higgs-like particles.

The LHC can take the first step in investigating this scenario by discovering multiple Higgs particles or uncovering other evidence, such as superpartners. Then linear collider experiments could detect a new source for the dominance of matter over antimatter.