The discovery of the Higgs particle would vindicate this theory of the Higgs mechanism by which particles acquire mass, and would therefore be a crucial moment in the history of particle physics. Cosmologists would also be particularly interested if the Higgs is proved to exist, as the existence of particles of this type is fundamental to the theory of inflation, which models the growth of the early Universe. The Higgs particle is part of the so-called Standard Model, a mathematical description of what we believe the ultimate components of matter and force look like. The Standard Model was given a huge boost last July, when scientists at Fermilab announced they had seen the tau neutrino - completing the 12 building blocks of matter that were predicted to exist. Fundamental to the modern understanding of particles is that they obey certain symmetries.
Group theory is a powerful mathematical technique for studying symmetry.
Thus, although group theory was invented as a purely mathematical idea with no known physical applications, it has turned out to be very important to particle physics. Experimental results led theorists to hypothesise a collection of particles that compose matter with a particular symmetry group, but this included particles that had never yet been observed. The tau neutrino was the last of them to be experimentally confirmed.