This morning Professors Peter Higgs and Francois Englert were awarded the Nobel Prize for Physics for their predictions, made in 1964, of a mechanism which explains how certain fundamental particles such as quarks and electrons acquire mass. The mechanism is a key constituent of the Standard Model, our best model for explaining the interaction of fundamental particles. The award crowns a pair of remarkable careers and concludes a gloriously romantic story.
Francois Englert spoke directly to the press following the announcement and declared that he was “extraordinarily happy to have the recognition of this extraordinary award”. He intends to congratulate Peter Higgs on the “very important and excellent work” which he completed during the 1960s.
Here are some of the key milestones on the long and remarkable journey of these two Nobel laureates.
A fortunate rejection
In August 1964, Robert Brout and Francois Englert of the Free University of Brussels published a landmark paper which detailed the mechanism by which elementary particles such as quarks and electrons acquire mass. At around the same time, Peter Higgs of Edinburgh University submitted two papers on what is now known as the Higgs field to the journal Physics Letters. The second of those papers was rejected – and a good thing it was too. Respected physicist, Yoichiro Nambu, who reviewed Higgs’ paper suggested that he may wish to elaborate on his theory’s physical implications. In response, Higgs added a paragraph which said that an excitation of the Higgs field would yield a new particle. This particle came to be known as the Higgs boson.
Higgs resubmitted the paper to an opposition journal, Physical Review Letters, which published it later in October 1964.
Accurate predictions but no cigar
In the mid 1990’s the Higgs was back in the public eye. Although it had not yet been observed, it had enabled the Standard Model to make a number of successful predictions, including the discovery of the top quark at 176 GeV made by Fermilab’s Tevatron.
Experiments at Fermilab’s Tevatron and CERN’s Large Electron Positron (LEP) Collider had concluded that the Higgs must exist above 117 GeV, but neither was sensitive enough to probe at these energy levels. Enter the mammoth Large Hadron Collider (LHC) into the fray in 2008. This beastly circular accelerator, with a circumference of 27 km and phenomenally powerful electromagnets, promised collision energies approaching 14 TeV. So the observation of the Higgs boson was considered, surely, imminent – until the LHC blew up after nine days of operation and was closed down for more than a year of repairs.
Patience Professors, patience…
On 4 July 2012 science’s worst kept secret was publicly announced at CERN, Geneva. Spokespersons of the ATLAS and CMS detectors announced that they had observed a ‘Higgs-like particle’ at 126 GeV and CERN’s Director General, Rolfe-Dieter Heur, declared – “I think we have it”. Peter Higgs sat in the room and shed a tear of joy. He also met a chap called Francois Englert for the first time that day.
And the winner is…
So it took almost 50 years, a $10 billion machine and the input of thousands upon thousands of scientists, engineers and mathematicians, but technology caught up with theory and proved Francois Englert and Peter Higgs right. There may be some grumblings that the observation of the Higgs boson also deserved the recognition of the Nobel Committee, but I think no one would begrudge these two extraordinary men science’s ultimate accolade. It has certainly been a long time coming.
Well done chaps – you thoroughly deserve it!