EFT Coffee: Heleen Mulder, "Probing hadronic CP violation with EDMs of paramagnetic molecules"

Friday 17 Apr 2026, 13:30 → 14:30 Europe/Zurich

4/2-037 - TH meeting room (CERN)

Electric Dipole Moments (EDMs) are CP-violating observables, which can be measured in a wide range of low-energy experimental systems. While no non-zero EDM has been measured yet, the strong upper bounds on EDMs allow us to bound possible underlying sources of (BSM) CP violation. In this talk, I will focus on how to interpret the bounds on the EDMs of paramagnetic molecules. The precision of EDM experiments working on these specific systems has increased rapidly over the last decade or so. While these increasingly precise bounds are usually translated to upper bounds on the electron EDM, paramagnetic EDMs also receive contributions through CP-violating electron-nuclear interactions. These effective interactions dominantly arise from hadronic sources of CP violation, like the QCD theta term and nucleon EDMs. Calculating electron-nuclear interactions involving meson exchanges or nucleon EDMs in an EFT framework, we have been able to translate paramagnetic EDM measurements to bounds on various hadronic sources of CP violation. While currently less stringent than equivalent bounds from diamagnetic atom and neutron EDM searches, we stress that the paramagnetic bounds are completely independent, and will be crucial in disentangling possible underlying sources of CP violation when non-zero EDM measurements appear.