2023 James Chadwick Medal and Prize

Professor Themis Bowcock has led the design and construction of key detector systems that underwrite and enable our understanding of quark decays at the Large Hadron Collider (LHC), as well as facilitating the discovery of new forms of matter (tetraquark and pentaquark bound states). He has led the design, construction and commissioning of three generations of the LHCb VELO detector that underpins all LHCb measurements, but particularly those searching for evidence of physics beyond the Standard Model of particle physics; for example, anomalous decay rates of the Bs meson to muons and enhanced CP-violation.

Without the VELO and Bowcock’s role in its design and construction, none of these measurements would have been possible with the precision achieved. The importance of the VELO in underpinning these landmark measurements is highlighted by the VELO being part of the Collider exhibit in the London Science Museum’s permanent collection and CERN’s historical exhibit (Microcosm).

Bowcock has also led detector developments that were crucial in the recent world’s best measurement of the anomalous magnetic moment of the muon (g-2) at Fermilab. He designed and led the construction of the low-mass strawtracking detectors that are responsible for measuring the muon’s beam motion in the storage ring and thus in minimizing the key systematic uncertainties of the measurement. This has led to developing detectors for future muon experiments at CERN and the Paul Scherrer Institute: MuonE and MuEDM.

He has also been one of the leading advocates in developing new quantum technologies; for example, the UK’s first atom interferometer searching for dark matter and in establishing the UK in the MAGIS experiment (low-mass dark matter, and low-frequency gravitational waves) and the AION programme.

Bowcock has made outstanding contributions to particle physics for several decades and his work was crucial for scientific breakthrough. The detectors that he has designed and built have been crucial for many of the most important measurement in quark flavour physics.