Results from the Muon g-2 and LZ experiments have been selected amongst the best papers published in Physics Review Letters in 2025. Both experiments are world-leading international collaborations with UCL researchers playing leading roles.
Muon g-2 published its final measurement of the magnetic moment of the muon, accurate to 127 parts-per-billion, the most precise measurement ever made at a particle accelerator. This is a high precision test of the Standard Model of particle physics, prompting significant activity in the theory community to match the level of understanding of this fundamental property of the muon.
The LZ experiment published the most sensitive direct search for dark matter, finding no evidence for dark matter particles of mass greater than 9 GeV/c2 (roughly ten times the mass of the proton). The nature of dark matter, which makes up ~27% of the Universe, remains a mystery. LZ will continue to search for dark matter, as well as probe beyond-the-Standard-Model neutrino interactions.
The Muon g-2 group at UCL is lead by Prof Gavin Hesketh, with Associate Professor Rebecca Chislett and Dr Alex Keshavarzi, and postdoc Dr Mikio Sakurai. Dr Lucy Bailey was awarded the UCL High Energy Physics thesis prize in 2025 for her work on the experiment.
The LZ group is lead by Prof Cham Ghag and Dr Amy Cottle, with postdocs Dr Aiham Al Musalhi, Dr Joe McLaughlin, Dr Joshua Green and visitor Dr Robert James, who previously won the UCL High Energy Physics thesis prize in 2024 for the statistical framework used in this result, and students Jacopo Siniscalco, Isabelle Darlington and Simran Dave all making contributions.
The image shows a photo-multiplier tube array from the LZ experiement.
The full PRL Collcation of the Year can be accessed by following this link.