Dr Benjamin Roberts

Working in theoretical atomic physics and particle astrophysics. My research focusses on high-precision atomic structure calculations, and how atomic processes can be used for testing fundamental theories, probing for physics beyond the standard model, and searching for dark matter. This is complimentary to the high-energy tests performed at CERN. Some research highlights include: searching for variations in the fundamental constants near the super-massive black hole at the centre of our galaxy [1]; using decades of archived atomic clock data from the GPS satellites to search for signatures of dark matter [2]; performing high-precision calculations of symmetry violations in atoms, allowing the most precise low-energy test of the standard model to date [3-5]; and proposing and quantifying novel experimental signatures of dark matter that exploit atomic (rather than the typical nuclear) phenomena, opening the door to a wide range of previously "invisible" models [6-9].

1. A. Hees, T. Do, B. M. Roberts, A. M. Ghez, S. Nishiyama, R. O. Bentley, A. K. Gautam, S. Jia, T. Kara, J. R. Lu, H. Saida, S. Sakai, M. Takahashi, and Y. Takamori, Search for a Variation of the Fine Structure Constant around the Supermassive Black Hole in Our Galactic Center, Phys. Rev. Lett. 124, 081101 (2020).
2. B. M. Roberts, G. Blewitt, C. Dailey, M. Murphy, M. Pospelov, A. Rollings, J. Sherman, W. Williams, and A. Derevianko, Search for Domain Wall Dark Matter with Atomic Clocks on Board Global Positioning System Satellites, Nature Comm. 8, 1195 (2017).
3. V. A. Dzuba, J. C. Berengut, V. V. Flambaum, and B. M. Roberts, Revisiting Parity Nonconservation in Cesium, Phys. Rev. Lett. 109, 203003 (2012).
4. B. M. Roberts and J. S. M. Ginges, Nuclear Magnetic Moments of Francium-207–213 from Precision Hyperfine Comparisons, Phys. Rev. Lett. 125, 063002 (2020).
5. G. Sanamyan, B. M. Roberts, and J. S. M. Ginges, Empirical Determination of the Bohr-Weisskopf Effect in Cesium and Improved Tests of Precision Atomic Theory in Searches for New Physics, Phys. Rev. Lett. 130, 053001 (2023).
6. B. M. Roberts, Y. V. Stadnik, V. A. Dzuba, V. V. Flambaum, N. Leefer, and D. Budker, Limiting P-Odd Interactions of Cosmic Fields with Electrons, Protons, and Neutrons, Phys. Rev. Lett. 113, 081601 (2014).
7. B. M. Roberts, V. V. Flambaum, and G. F. Gribakin, Ionization of Atoms by Slow Heavy Particles, Including Dark Matter, Phys. Rev. Lett. 116, 023201 (2016).
8. B. M. Roberts et al., Search for Transient Variations of the Fine Structure Constant and Dark Matter Using Fiber-Linked Optical Atomic Clocks, New J. Phys. 22, 093010 (2020).
9. E. Savalle, A. Hees, F. Frank, E. Cantin, P.-E. Pottie, B. M. Roberts, L. Cros, B. T. McAllister, and P. Wolf, Searching for Dark Matter with an Optical Cavity and an Unequal-Delay Interferometer, Phys. Rev. Lett. 126, 051301 (2021).