The particle physics group is addressing fundamental questions about the building blocks of matter and the basic forces of nature with a diverse programme of activities at CERN's Large Hadron Collider and at various facilities dedicated to the investigation of neutrino interactions.

Lancaster is a founder member of the ATLAS experiment at the Large Hadron Collider in Geneva, where we study proton-proton collisions at the highest energies achieved so far, 13 TeV. The group has many interests; in particular, we are looking for signatures of new physics using beauty hadrons, jets of particles and top quarks. One major focus is identifying the reason for the absence of antimatter in the everyday world. We are also investigating the properties of the recently-discovered Higgs boson, and using the Higgs as a tool to search for new physics. During the few first years of LHC running we played a part in the Higgs boson discovery, and we were pleased to discover the first new particle seen at the LHC, the χb(3P). We are now looking for new particles beyond the ‘standard model’ that live long enough to decay in the tracking system.

These physics activities motivate our practical studies of detectors that precisely track the particles from the collisions, and the development of distributed computing in the form of Grids and Clouds. We also work on the tracking system for the future upgraded ATLAS detector, and have a leading role in the computing and software evolution.

Our ATLAS work contributed to the 2013 Nobel Prize and Breakthrough Prizes.

Lancaster has just  joined NA62, a cutting edge experiment at CERN designed to study the physics of kaons. NA62 will search for new physics at energy scales up to 100 TeV by observing and studying the ultra-rare decay of a charged kaon (K±) to a charged pion (π±), a neutrino and an anti neutrino (which only occurs in one in 1010 decays). NA62 is also searching for dark matter candidates such as heavy neutral leptons, dark photons and axion-like particles as well as looking for differences between matter and anti-matter.

Our neutrino physics programme spans several accelerator and non-accelerator experiments.

The accelerator experiments allow us to study the transformation of one sort of neutrino into another and to search for differences between neutrinos and their antimatter versions, antineutrinos. The T2K experiment in Japan has shown the first hints that this so-called "CP violation" is non-zero, through precise measurements of the appearance of one type, electron neutrinos, in a beam of muon neutrinos. Lancaster has several leadership roles in T2K and built key components of the “ND280” near detector. Lancaster is also a member of the MINOS+ experiment, which operates at the Fermi Laboratory, USA. MINOS+ has made precision measurements of oscillations using accelerator neutrinos, and is currently conducting searches for new phenomena such as hypothesised “sterile” neutrinos. Our physics goals centre on measuring the probability of the neutrino interactions with matter. In addition, Lancaster is preparing the upcoming neutrino experiments DUNE and SBND in the US, and Hyper-Kamiokande in Japan to study similar questions in much greater detail. With the MicroBooNE experiment in the US we are developing analysis tools for new liquid-argon neutrino detectors, and at the same time searching for the hypothesized “sterile” neutrinos.

SNO+, our non-accelerator experiment in Canada, is testing whether or not neutrinos are their own antiparticles, which would have profound implications for both particle physics and cosmology.

Our SNO and T2K work contributed to the 2015 Nobel Prize and Breakthrough Prizes.