François Englert of Higgs boson fame passes away at 93

The Belgian physicist and Nobel laureate François Englert passed away on June 18 aged 93. Englert’s contributions changed the way physicists understood the fundamental nature of the universe.

Englert’s parents were Polish-Jewish immigrants. He survived the Holocaust by moving between orphanages and foster homes to evade Nazi persecution. He spent most of his professional life in the Université libre de Bruxelles, where he obtained his PhD in 1959.

Englert is best known for his work in the early 1960s about how subatomic particles get their property of mass. In 1964, together with the American-Belgian physicist Robert Brout, he published a landmark paper titled ‘Broken Symmetry and the Mass of Gauge Vector Mesons’. It proposed what is now known as the Brout-Englert-Higgs (BEH) mechanism.

Brout and Englert theorised that the vacuum of space is not empty but filled with a fundamental field. By interacting with this field, otherwise massless particles would acquire the property of mass.

This work solved a critical problem in the Standard Model, which is the main theoretical framework of particle physics.

At the time, physicists struggled to explain why some fundamental particles, like the W and Z bosons, had mass while others, like the photon, did not. Englert and Brout’s paper, developed independently but simultaneously with the British physicist Peter Higgs, provided the missing piece of the puzzle.

Belgian physicist Francois Englert (left) and British physicist Peter Higgs at CERN on July 4, 2012.
| Photo Credit:
AFP

A third paper by Gerald Guralnik, C. Richard Hagen, and Tom Kibble was published shortly after, but also in 1964, and it offered a more mathematically rigorous proof of the BEH mechanism. It was essential to completing the theoretical framework.

This is why the discovery is often called the Brout-Englert-Higgs-Guralnik-Hagen-Kibble (BEHGHK) mechanism within the scientific community — a mouthful but also more accurate.

While Higgs’s version of the theory specifically highlighted the existence of a corresponding particle, called the Higgs boson, it was the collective insight of these researchers that established the mechanism as a cornerstone of modern physics.

The world waited nearly half a century for physicists to experimentally confirm that the Higgs boson exists, which they did in 2012 at the CERN Large Hadron Collider. Englert and Higgs were both present at the announcement. The pair subsequently won the 2013 Nobel Prize for physics. (Brout had passed away in 2011.)

Beyond the Higgs boson, Englert contributed to statistical physics and quantum field theory. In his later years, he turned his focus to cosmology and string theory and sought to reconcile quantum mechanics with general relativity — perhaps modern physics’s greatest unsolved problem.

As a professor emeritus at the Université libre de Bruxelles and a recurring scholar at the Tel Aviv and Chapman Universities, Englert also engaged in the philosophy of reality.