I work with at the intersection between particle and nuclear physics. In particular I am interested in the role played by the symmetries of quantum chromodynamics (QCD) in the structure and interactions of nucleons and mesons. The most important of these symmetries of the strong interaction is a chiral symmetry which is respected by up and down quarks (the ones we are made of) because they have very small masses in QCD. The strong attraction between quarks and antiquarks means that "empty" space is filled with a Bose-Einstein condensate of quark-antiquark pairs,
which acts like a Higgs field and hides the chiral symmetry. My work takes advantage of the way pions (the lightest mesons) "remember" this symmetry in their interactions. It makes use of a range of theoretical
techniques including effective field theory and the renormalisation group.
I am also interested in transitions from ordinary nuclear matter to new phases such as a quark-gluon plasma or a colour superconductor. The plasma is the phase of matter which existed shortly after the Big Bang, and which may be recreated by colliding heavy nuclei together at ultrarelativistic energies. Colour-superconducting quark matter may exist at very high densities in the centre of neutron (or quark) stars.
