Dan did his DPhil at the University of Oxford where he analysed multi-body decays of charm mesons using data from the CLEO III and CLEO-c experiments (Cornell University, USA), and pursued high-precision measurements of CP violation in the decays of beauty particles using data from the newly-inaugurated LHCb experiment (CERN, Switzerland). Moving to CERN as a Research Fellow, and later a Staff member, he focussed on measurements that test models of quantum chromodynamics: studies of 'diffractive' proton-proton interactions (where protons interact but, unusually for the LHC, do not always fragment) as well as searches for new hadrons consisting of quarks in exotic arrangements.
Later at MIT, and now at Birmingham, Dan's focus turned to dark matter; well established in theory and astronomy but - after many years of searching - still lacking a particle explanation. He is using LHCb data, and planning for future long-lived-particle-search experiments at the High-Luminosity LHC, to undertake new searches for particles that, if discovered, would open the doorway to a secret garden - a 'dark sector' - of new particles and interactions that could fill this gap.