2017 John William Strutt, Lord Rayleigh Medal and Prize

Professor Nigel Glover of Durham University for pioneering new methods for the application of perturbative quantum chromodynamics to high-energy processes involving energetic jets, leading to sophisticated simulation codes that are being used to describe LHC data.

Professor Nigel Glover has made numerous contributions to the interpretation of data collected at the high-energy colliders at CERN and the Tevatron.

He is especially distinguished for his contributions to the development and exploitation of the perturbative structure of quantum chromodynamics to make state-of-the-art predictions of scattering cross-sections for processes involving electroweak vector bosons, Higgs bosons and particularly jets.

In the 1990s, Glover pioneered the description of QCD processes at next-to-leading order in the strong coupling, which were fully differential in the jet variables – thereby modelling the experimental setup precisely. Technical innovations, including the use of helicities for QCD loop amplitudes, the systematic extraction of infrared singularities and the evaluation of loop processes with five legs, led to codes that were widely used by the experimental communities at LEP and the Tevatron to analyse their data. For example, the determination of the strong coupling constant in di-jet events at the Tevatron, or the determination of the photon fragmentation function in the presence of isolation cuts at LEP.

Faced with the challenge of very precise scattering data from the LHC, Glover has established a new standard of theoretical precision for the description of jet observables at next-to-next-to-leading order (NNLO). In a series of theoretical papers, the universal factors that describe the infrared structure in the regions where two partons are unresolved were identified, the two-loop amplitudes relevant for di-jet production in hadron–hadron collisions and three-jet production in electron–positron annihilation were computed, and a full scheme for isolating and subtracting the infrared divergences was developed.

Combining these developments led to the first full NNLO prediction for hadronic event shapes in electron–positron annihilation and an improved QCD analysis of event shapes and jet rates using LEP data, and the first NNLO predictions for di-jet, Z-plus-jet and Higgs-plus-jet events at the LHC.

Glover was elected as a Fellow of the Royal Society in 2013.