RAL physicists have built a significant part of the 1000 tonne SOUDAN IIdetector housed in a mine in Minnesota. Protons are expected to live forbillions and billions of years, but there are billions and billions of protonsin 1000 tonnes of material, so if they do decay, even if it is only a few peryear, SOUDAN II should detect the events.
The search for 'dark' matter also needs to take place as far from the 'background noise' of cosmic rays at the Earth's surface. RAL has installed adetector 1 km underground in a mine near Whitby in Yorkshire to look for apossible explanation of this mystery.