A composite image showing the galaxy cluster known as the Bullet Cluster, displaying clear separation seen between normal and dark matter.

Sussex researchers, led by Prof Antonella De Santo, have received funding to join a consortium of UK researchers that have begun designing a new device to detect the elusive dark matter particles in our Universe.

A preliminary award of £8 million from the UK Research and Innovation (UKRI) Infrastructure Fund will support a consortium of UK universities^(*) to work with the Science and Technology Facilities Council (STFC) Boulby Underground Laboratory over the next three-and-a-half years.

As part of the world-leading Xenon Lux-Zeplin Darwin (XLZD) Consortium for dark matter research, the team will contribute to the development of initial plans and design components for the world’s largest and most advanced dark matter detector. Once completed, this international experiment could be hosted at the UK’s deep underground science facility at Boulby mine in the North-East of England.

Dark matter is a hypothetical form of matter thought to make up more than 85% of the mass content of the Universe, and whose evidence for existence comes from a range of observations across many scales in the Universe, such as the Bullet Cluster (see image).

The XLZD observatory will explore the fundamental laws of physics and act as a telescope for the nature and composition of our Universe, searching for dark matter particles and for new neutrino physics. The experiment has the potential to change our understanding of physics in the same way that CERN’s Large Hadron Collider did when it detected the Higgs Boson particle in 2012.

The detector will consist of a large underground 'thermos flask' containing up to 100-tons of liquid xenon, which scientists believe will react subtly with dark matter as it passes through the Earth. Tiny, but detectable, flashes of light will be generated as evidence of the presence of dark matter particles and recorded for scientists to analyse.

The Sussex team are becoming involved in the design of the so-called Outer Detector component of the experiment, which is essential to enable XLZD's mission as a rare event observatory.  

Prof De Santo, who in 2009 established the Sussex ATLAS group, making leading contributions to one of the two experiments that in 2012 discovered the Higgs boson at CERN’s world-renowned Large Hadron Collider, said:

“This is an exciting new research adventure at the frontiers of fundamental physics knowledge. As the founder and leader of Sussex’s world-class ATLAS research group working at the ‘energy frontier’ at CERN, and myself a long-time dark matter hunter at the Large Hadron Collider, I am excited to be spearheading this new Sussex effort at the 'cosmic frontier'.

"The XLZD project holds well-founded promises of groundbreaking discoveries and of fundamental advancements in years to come, with strong UK investment and leadership. It is fantastic news for Sussex to be part of this effort.”

(*) Universities involved/funded: Birmingham University; Bristol University; Edinburgh University; Imperial College London [Lead]; King’s College London; Liverpool University; Oxford University; Queen Mary, University of London; Royal Holloway, University of London; Sheffield University; STFC Daresbury Laboratory; STFC Rutherford Appleton Laboratory; University of Sussex.

Image credits: X-ray: ASA/CXC/CfA/M.Markevitch et al.; Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al.; Lensing Map: NASA/STScI; ESO WFI; Magellan/U.Arizona/D.Clowe et al.