The Standard Model of particle interaction describes the interactions of all the constituent of the matter to an impressive degree of accuracy. One of the successes of this model is the unification of the electromagnetic and the weak interactions into a new sector called the Electroweak sector. In this model, the Electroweak sector is characterised by a breaking of the SU(2) × U(1) gauge group, which explains why the photon is massless while the W and Z bosons (the mediators of the weak force) have a mass. The electroweak breaking is due to the widely known and notoriously elusive Higgs sector, which describes the interactions of a new particle, the Higgs boson. In addition to giving mass to the mediators of the weak force, the Higgs boson provides mass for ordinary fermionic matter (leptons and quarks). However this elegant model is believed to be valid only up to a certain energy scale, above which new physics is bound to manifest.
Many models have been proposed over the years to explain the theory at the scales of new physics. Technicolor is the framework according to which Electroweak symmetry breaking is due to the breaking of the chiral symmetry in a new strong interaction. The model proposes a different answer to the origin of all particles masses, by means of a new mechanism to generate mass for the leptons. These ideas are inspired a similar mechanism that is already at work in the theory of the strong interactions, Quantum Chromodynamics (QCD). A fundamental requirement for any beyond the Standard Model theory is that the framework does not spoil any lower energy prediction, i.e. that they are compatible with current observation. This is a severe constraint, which in Technicolor is implemented by the mechanism of walking, i.e. the slow running of the gauge coupling in an intermediate range of energies. This happens for near-conformal gauge theories. The question then becomes: is there a near-conformal gauge theory that can account for the observed Electroweak symmetry breaking?
The resources offered by the Dirac consortium allowed us to perform Monte Carlo simulation for a theory that has been conjectured be a candidate for the realisation of the Technicolor framework. The model, called Minimal Walking Technicolor, is an SU(2) gauge theory coupled with two adjoint Dirac fermion flavours. We proved that (near-)conformality can be rephrased as a mass spectrum with constant mass ratios between the particles when the constituent fermion mass goes to zero and we observed this feature numerically.