Research

My current research interests are in engaging underrepresented groups in STEM, methods of informal science learning and education, and effective ways of communicating science to the public. During my PhD, my research was in quantum chromodynamics (Theoretical Physics Division, University of Liverpool).

Previous research publications:

  • Bilinear quark operator renormalization at generalized symmetric point, J. M. Bell, J. A. Gracey, Phys. Rev. D93 (2016) 065031 – Abstract: We compute Green’s functions with a bilinear quark operator inserted at nonzero momentum for a generalized momentum configuration to two loops. These are required to assist lattice gauge theory measurements of the same quantity in matching to the high energy behaviour. The flavour nonsinglet operators considered are the scalar, vector and tensor currents as well as the second moment of the twist-2 Wilson operator used in deep inelastic scattering for the measurement of nucleon structure functions.
  • Maximal abelian and Curci-Ferrari gauges in momentum subtraction at three loops, J. M. Bell, J. A. Gracey, Phys. Rev. D – Abstract: The vertex structure of QCD fixed in the maximal abelian gauge (MAG) and Curci-Ferrari gauge is analysed at two loops at the fully symmetric point for the 3-point functions corresponding to the three momentum subtraction (MOM) renormalization schemes. Consequently the three loop renormalization group functions are determined for each of these three schemes in each gauge using properties of the renormalization group equation.
  • MOM renormalization group functions in the maximal abelian gauge, J. M. Bell, J. A. Gracey, Phys Rev D88 (2013) 085027 – Abstract: The one loop 3-point vertex functions of QCD in the maximal abelian gauge (MAG) are evaluated at the fully symmetric point at one loop. As a consequence the theory is renormalized in the various momentum (MOM) schemes which are defined by the trivalent vertices, as well as in the MSbar scheme. From these the two loop renormalization group functions in the MOM schemes are derived using the one loop conversion functions. In parallel we repeat the analysis for the Curci-Ferrari gauge which corresponds to the MAG in a specific limit. The relation between the Lambda parameters in different schemes is also provided.