Dr Benjamin Roberts

Postdoctoral Research Fellow

School of Mathematics and Physics
Faculty of Science

Overview

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.

Research Interests

  • Atomic structure theory
  • Low-energy tests of fundamental physics
  • Dark matter
  • Particle astrophysics

Publications

View all Publications

Available Projects

  • Develop and test atomic methods for calculating dark matter interactions with atoms. This includes atomic excitation and ionisation caused by the scattering and/or absorption of dark matter particles by atoms.

    The project will involve aspects of quantum mechanics (elementary atomic theory, scattering theory) and particle astrophysics (application to dark matter direct detection experiments, and interpretation of results in terms of dark matter and particle physics models). It will also involve some basic programming (in c++ and/or python), though no prior knowledge of programming is required.

    For some details, see: * "Electron-interacting dark matter: Implications from DAMA/LIBRA-phase2 and prospects for liquid xenon detectors and NaI detectors." Physical Review D, 100, 063017 (2019) [http://arxiv.org/abs/1904.07127]

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  • Atomic physics calculations involve treating the many-electron atomic Hamiltonian approximately. In order to achieve high accuracy, a number of many-body effects need to be taken into account using perturbation theory.

    One such class of effects, known as "ladder diagrams", are missing from some calculations. Though small, these corrections seem to be important in some cases.

    The ladder-diagram method has been applied previously to energies with high success (see: Physical Review A, 78, 042502.) The plan here is to extend this method to include "ladder diagram" corrections directly into atomic wavefunctions. These wavefunctions can then be used to compute relevant atomic properties (for example, hyperfine splittings, transition rates, lifetimes etc.).

    The project will involve aspects of quantum mechanics (elementary atomic theory) and numerical methods (application of existing code libraries to new problems in atomic physics). It will also involve some basic programming (in c++ and/or fortran), though no prior knowledge of programming is required.

View all Available Projects

Publications

Featured Publications

Journal Article

Conference Publication

  • Flambaum, V. V., Dzuba, V. A., Pospelov, M., Derevianko, A. and Roberts, B. (2015). Atomic ionization by dark matter particles. 29th International Conference on Photonic, Electronic, and Atomic Collisions (ICPEAC), Toledo, Spain, 22-28 July 2015. Bristol, United Kingdom :Institute of Physics Publishing. doi: 10.1088/1742-6596/635/2/022012

  • Roberts, B. M., Stadnik, Y. V., Dzuba, V. A., Flambaum, V. V., Leefer, N. and Budker, D. (2015). New atomic methods for dark matter detection. 29th International Conference on Photonic, Electronic and Atomic Collisions, ICPEAC 2015, Toledo, Spain, 22-28 July 2015. Bristol, United Kingdom :Institute of Physics Publishing. doi: 10.1088/1742-6596/635/2/022033

  • Roberts, Benjamin M., Stadnik, Yevgeny V., Flambaum, Victor V. and Dzuba, Vladimir A. (2015). Searching for axion dark matter in atoms: oscillating electric dipole moments and spin-precession effects. Patras Workshop on Axions, WIMPs and WISPs, Zaragoza, Spain, 22-26 June 2015. Hamburg, Germany :Verlag Deutsches Elektronen-Synchrotron. doi: 10.3204/DESY-PROC-2015-02/robertsbenjaminaxions

  • Stadnik, Yevgeny V., Roberts, Benjamin M., Flambaum, Victor V. and Dzuba, Vladimir A. (2015). Searching for scalar dark matter in atoms and astrophysical phenomena: variation of fundamental constants. Patras Workshop on Axions, WIMPs and WISPs, Zaragoza, Spain, 22-26 June 2015. Hamburg, Germany :Verlag Deutsches Elektronen-Synchrotron. doi: 10.3204/DESY-PROC-2015-02/robertsbenjamin

Possible Research Projects

Note for students: The possible research projects listed on this page may not be comprehensive or up to date. Always feel free to contact the staff for more information, and also with your own research ideas.

  • Develop and test atomic methods for calculating dark matter interactions with atoms. This includes atomic excitation and ionisation caused by the scattering and/or absorption of dark matter particles by atoms.

    The project will involve aspects of quantum mechanics (elementary atomic theory, scattering theory) and particle astrophysics (application to dark matter direct detection experiments, and interpretation of results in terms of dark matter and particle physics models). It will also involve some basic programming (in c++ and/or python), though no prior knowledge of programming is required.

    For some details, see: * "Electron-interacting dark matter: Implications from DAMA/LIBRA-phase2 and prospects for liquid xenon detectors and NaI detectors." Physical Review D, 100, 063017 (2019) [http://arxiv.org/abs/1904.07127]

    -

  • Atomic physics calculations involve treating the many-electron atomic Hamiltonian approximately. In order to achieve high accuracy, a number of many-body effects need to be taken into account using perturbation theory.

    One such class of effects, known as "ladder diagrams", are missing from some calculations. Though small, these corrections seem to be important in some cases.

    The ladder-diagram method has been applied previously to energies with high success (see: Physical Review A, 78, 042502.) The plan here is to extend this method to include "ladder diagram" corrections directly into atomic wavefunctions. These wavefunctions can then be used to compute relevant atomic properties (for example, hyperfine splittings, transition rates, lifetimes etc.).

    The project will involve aspects of quantum mechanics (elementary atomic theory) and numerical methods (application of existing code libraries to new problems in atomic physics). It will also involve some basic programming (in c++ and/or fortran), though no prior knowledge of programming is required.