This is an English translation of “La passione di un fisico romantico“,
published in the Vatican’s The Roman Observer April 11.
Click here for the original from The Roman Observer.
Peter Higgs, the 2013 Nobel Prize winner for Physics died on 8 April 2024. He represents a generation of “romantic” theoretical physicists who did physics out of pure passion. He celebrated the fact that in his life he had not written as many articles as would be needed today to find a position in physics. His theory is very deep and complicated, but it was verified experimentally more than fifty years after its formulation. His name is above all linked to the Higgs particle (boson) and the Broet-Englert-Higgs mechanism in the theory of elementary particles of the standard model of fundamental interactions (named for the three physicists who proposed it independently). The model describes the electrical and magnetic (electromagnetic) force, and the weak and strong nuclear forces (in atomic nuclei). The electromagnetic and weak nuclear interaction have already been unified, in the standard model, in a theory called electroweak (where the Higgs mechanism was used first) and verified at CERN in 1983. The standard model excludes, for now, gravity because a theory that combines quantum mechanics and gravity (quantum gravity) is not yet known and is a subject of investigation.
The standard model was already fully understood towards the end of the 1970s. It is based on the assumption that there is a symmetry, called gauge symmetry, which together with another symmetry, called chiral, does not allow elementary particles to have an inherent mass, measurable when they are at rest. The Higgs field interacts with all these massless particles. It has a potential with a symmetry that respects that of the electroweak gauge group. At low energies this symmetry breaks due to a phenomenon called “spontaneous symmetry breaking” and the elementary particles, except the photon and neutrinos, acquire mass by virtue of the “Higgs mechanism”.
Now we know for sure that, in the history of the universe, before 10-11 seconds after the Big Bang, by virtue of what was said above, the particles had no mass. As the universe expanded, it cooled to low energies, and due to the Higgs mechanism the elementary particles acquired the masses we now know, including the Higgs particle itself. In the years from 1978 to 2012, the largest particle accelerators in the world searched for a trace of the Higgs boson, without finding it. The experimental physicists Leo Ledermann and Dick Teresi wrote a book in 1993 on the Higgs particle which they renamed “the God particle” because it was “elusive” like God. Much embroidered on to this statement over time, but there is really nothing connecting God and the Higgs boson, other than excessive speculation. In 2012 the Large Hadron Collider at Cern revealed the presence of the Higgs particle with a mass value of 126 GeV (Giga electron volt, a unit of energy-mass in elementary particles).
by Gabriele Gionti
Jesuit Father, Vatican Observatory
