Research

My work focuses on the fundamental physics of the Standard Model and beyond.

Muon g-2

The Muon g-2 experiment at Fermi National Accelerator Laboratory (USA) is making precision measurements of the muon.

The main aim is a the world’s most precise measurement of the muon’s anomalous magnetic dipole moment (g-2). Publications based on the first data-taking periods garnered international headlines as they show significant (>5 σ) tension with data-driven theory predictions. More recent lattice calculations show much lower tension, however.

I also work on the search for an electric dipole moment (EDM) of the muon at Muon g-2. The EDM is effectively zero in the Standard Model, but can be enhanced by many beyond-the-Standard Model scenarios - particularly those which aim to explain the matter-antimatter asymmetry in the universe.

Muon g-2 completed data-taking in 2023 and we are now analysing the full dataset for the g-2 and EDM analyses.

Mu3e

The Mu3e experiment at the Paul Scherrer Institut (Switzerland) will search for the decay μ→eee. This process is essentially forbidden in the Standard Model, but is significantly enhanced in many beyond-the-Standard Model scenarios. Any observation of this decay will constitute direct evidence for BSM physics; in the absence of an observation, Mu3e will exclude BSM physics at energy scales far beyond those directly accessible at the LHC. Mu3e is currently under construction.

MuEDM

The MuEDM experiment at the Paul Scherrer Institut (Switzerland) is a dedicated search for the electric dipole moment of the muon. MuEDM will extend the sensitivity by three orders of magnitude over current limits, and will for the first time probe into the theoretically interesting region below \(10^{-21} e\cdot\)cm with a target sensitivity of around \(6\times10^{−23}e\cdot\)cm.

MuEDM phase-1 is currently under construction.

History

At the Tevatron and LHC, I have previously worked on searching for new physics in unconventional signatures, precision QCD measurements (including g→bb splitting), Higgs searches, precision electroweak measurements, cosmic ray physics, and phenomenological studies based on these results: developing both searches and measurements to be used for testing and tuning theoretical models, as well as reinterpreting in the light of new theories.

In 2009 I wrote a short Les Houches article on lepton definitions (see Section 14), which lead to the adoption of born/dressed/bare lepton definitions. It’s not every day you get to redefine the electron!

Study

There are a range of opportunities to carry out research at UCL.

If you are interested in carrying out a PhD on g-2 or Mu3e, please do get in touch. Details of our programme can be found at www.hep.ucl.ac.uk/postgrad

Most years I also run projects on muon physics as part of the MSc and MSci programmes at UCL. Details on the moodle pages.

I also run 3rd year group projects on muon physics. Again, details are on the moodle.