95% of the energy density in the Universe is missing. Some of it is in the form of dark matter which helps explain the structures of galaxies and clusters of galaxies. We would like to learn more about this dark matter.
This is not the first time that mankind has had indirect indications that there might be another form of matter in the Universe which has not been detected, in the 20th century there were indications that mysterious invisible particles existed called neutrinos but initially it was thought that we would never be able to detect them. Eventually these neutrinos were indeed detected and are now well studied, giving us information about the Sun, astrophysics, the Earth and the Universe.
We would like to do the same thing with dark matter, we would like to detect it and then use it to understand the Universe and how it operates. The trouble is that we don't know what the dark matter is or how we might be able to detect it.
There are a class of well motivated models for dark matter which suggest that we should be able to detect it in several ways, by creating the dark matter at particle colliders such as the LHC, by detecting the dark matter in sensitive instruments deep underground and by looking for the dark matter annihilating with itself up in space. There are however a few problems with this class of models. We don't know precisely what form the dark matter might take within the context of these models and we certainly haven't seen any of it yet. What's more as our underground detectors become more and more sensitive, we still haven't seen any indications of the presence of dark matter. As the detectors become more and more sensitive, we expect them to also start to see neutrinos from the Sun and from cosmic rays. These neutrinos create a dangerous background that we are unable to overcome, which will mean that it will be difficult to detect any dark matter, should it show its face in this way.
We also don't know precisely how the dark matter is likely to show up at particle colliders, we have some ideas, but we don't know how well motivated these are. At the same time, the scientists working at the LHC need precise predictions in order to be able to work out exactly what to look for.
The main goals of our project is therefore to think about what kind of agnostic approaches we can take to these models of dark matter. Which particle physics models are most mathematically consistent with the rest of particle physics? What predictions do they make? We are also motivated to learn whether it is possible to mitigate against the neutrino background in dark matter detectors, or, if not, to turn our enemy into our friend and use dark matter detectors to learn more about neutrinos.
In this project we have developed many techniques to study these different issues in new ways and we have learnt more about dark matter, neutrinos and the history of the Universe.
