Jack Cassidy - Student Profile
Current Research Project:
Many-body Theory of Positron Interactions with Molecules
I am a member of the Green Group, led by Dr Dermot Green, helping to deliver the objectives of the ERC funded research programme “ANTI-ATOM: Many-body theory of antimatter interactions with atoms, molecules and condensed matter”, which aims to develop state-of-the-art ab initio theoretical and computational descriptions of positron interactions with atoms, molecules and condensed matter.
There is much experimental data on positron binding, scattering and annihilation with molecules, but there is currently no well-developed ab initio theory to explain the experimental observations. Our aim is to develop such a theory by properly accounting for the effects of electron-positron correlations ab initio via the use of diagrammatic many-body theory, where the various contributions to the amplitude of a positron-molecule interaction process (e.g. scattering, binding etc.) are represented by intuitive and transparent diagrams. Each diagram has a one-to-one mapping with an analytical expression, hence providing a systematic method to numerically calculate the contributions to the quantum mechanical amplitude of the process. We implement the diagrammatic approach via state-of-the-art computational methods developed by our group and collaborators.
Born and raised in Belfast, I graduated 1st class Applied Mathematics and Physics at QUB (2020), receiving the William Blair Morton Prize and the Philip Burke Memorial Award. My MSci research project, supervised by Dr Gleb Gribakin and Dr Andrew Swann, focussed on developing model-calculations of positron binding and bound-state annihilation with nitrile, aldehyde and ketone molecules. I began my PhD in the Green group in CTAMOP in October 2020.
- Quantum theory of many-body systems
- Diagrammatic many-body theory
- Positron interactions with molecules
- Atomic and molecular physics