I am a member of the Particle Physics Theory group at the University of Edinburgh. I joined the department in the Fall of 2020 with support from an exciting new initiative targeting a wide variety of UK-based researchers: The UKRI Future Leaders Fellowship. I go by ‘Max’, but I use my full name for publications.
Before joining the School of Physics and Astronomy at the University of Edinburgh, I spent time as a postdoctoral fellow at the Helmholz Institute Mainz, Germany, and as a fellow, and later a staff member, in the Theory Department at CERN, the European Organization for Nuclear Research in Geneva, Switzerland. I completed my PhD in 2014, under the exceptional mentorship of my advisor and collaborator, Steve Sharpe.
PhD in Theoretical Particle Physics, 2014
University of Washington, Seattle
BA in Physics, 2009
This is an informal summary of: Variations on the Maiani-Testa approach and the inverse problem. The idea of this work, completed with Mattia Bruno at CERN, is to connect some new ideas for calculating scattering amplitudes via lattice QCD with a seminal publication on the topic, the work of Maiani and Testa published in 1990.
This is an informal summary of: The energy-dependent $\pi^+ \pi^+ \pi^+$ scattering amplitude from QCD, published in PRL. In some ways, this work represents the culmination of a many-year effort going back to my PhD thesis in 2014.
This is an informal summary of: The role of boundary conditions in quantum computations of scattering observables. There has recently been a major push, worldwide, to accelerate the development of quantum technologies and especially quantum computing.
Acceptance of the Kenneth G. Wilson Award for Excellence in Lattice Field Theory.
In this talk, I will present a lattice-QCD calculation of the maximal-isospin, three-pion scattering amplitude (3π+ to 3π+). The calculation combines finite-volume energies with a relativistic field-theoretic formalism, required to interpret the results. I will describe the full work-flow required to reach the final amplitude, implemented here for the first time, and discuss the complicated singularities appearing in the latter. Finally I will discuss prospects for applying these methods to resonant three-particle systems, in order to gain a deeper understanding of these complicated objects from first principles QCD.
Numerical lattice calculations provide a powerful method for systematically estimating finite-volume Euclidean correlators. To connect to physical observables, one must analyze the role of the Euclidean signature and finite volume, as well as other systematic effects. In this seminar, I will discuss recent work on interpreting multi-hadron observables as spectral functions, given by inverting the Laplace transform on a particular lattice correlator. I will describe methods for regulating this notoriously ill-posed problem by targeting a smeared spectral function. This “smearing" turns out to be of great physical importance, e.g. for defining the infinite-volume limit and for implementing the required i-epsilon pole prescription. I will further discuss how this can be understood as an extension of the famous work of Maiani and Testa on Euclidean correlators. These methods are expected to be most relevant in quantities with many hadronic intermediate states including long distance contributions to heavy meson mixing and decays.
The strong force is governed by the elegant mathematical framework of quantum chromodynamics (QCD). The building blocks of QCD are quarks and gluons, and the interactions of these constituents lead to a rich variety of observed phenomena, from the basic properties of nuclei to the production of heavy elements in stars. A particularly intriguing aspect of QCD is the nature of resonances, short lived states that decay via the strong force. Many exotic resonances have been discovered over the last decade, with properties that are not easily described in simplified models of QCD. In addition, such excitations can dramatically affect the properties of electroweak decays so that a detailed understanding is crucial for expanding searchers of new physics beyond the Standard Model. In this talk I will discuss progress in theoretically controlling such effects in a rigorous and quantitative way by combining field theoretic ideas with large scale computer simulations in the framework of lattice QCD.