In the zoo of elementary particles which make up our universe, there is only one particle named after a person. Peter Higgs, after whom the eponymous Higgs boson is named, passed away recently at age 94 in Edinburgh.
Almost exactly 60 years ago, Higgs proposed a mechanism which could give elementary particles like electrons and quarks a mass. This was essential since the underlying theory which explained the interaction of particles had no consistent mechanism to generate masses for particles. Independently, several others including Brout, Englert and Kibble had also stumbled upon a similar mechanism. The idea, which had also been proposed earlier by Philip Anderson in the context of superconductivity, was built upon the work of the Nobel Laureate Y Nambu and J Goldstone.
The theory proposed by Higgs and others did not find favour with the particle physics community at first. However, by the early 1970s, it had been refined and became an essential part of the so-called Standard Model of Particle Physics that we believe explains the sub-microscopic reality.
Although theoretically, the model was consistent and predictive, the missing link was still the Higgs particle. The mechanism which was thought to give masses to all massive particles also predicted the existence of this unusual particle which had not been detected. The clinching evidence for the validity of the theory could only come from the actual detection of this elusive particle. But this was difficult given the state of the accelerator technology in the 1970-80s.
The search for the Holy Grail of particle physics, as the Higgs search came to be known, took more than three decades, billions of dollars, a multinational collaboration with thousands of scientists and some clever technology. In 2008, the Large Hadron Collider (LHC) at CERN in Geneva, the most powerful particle accelerator in the world, was finally commissioned. On July 4, 2012, a new particle which could be the Higgs boson was discovered at the LHC. It took another few months before it could be definitely said that this was indeed the Higgs boson. Higgs and Englert were given the Nobel Prize in 2013 for their theoretical prediction of this particle (Brout had died in 2011 and Nobel Prizes are not given posthumously).
Peter Higgs, who was an emeritus professor at the University of Edinburgh at the time of his death, was not just a brilliant scientist but also a great teacher with a flair for explaining very complex concepts in a simple, yet profound way. Despite his fame and recognition, he was an exceptionally modest person. He was also notoriously shy of any publicity and, on the day the Nobel Prize was announced, went to a seafood bar to escape media attention. He apparently did not possess a mobile phone.
Even though the name Higgs boson is widely accepted now, it did lead to some controversy in the particle physics community. This was simply because the idea not only had a longer history but also because several groups had independently proposed something similar. Some particle physicists thought that it was unfair to the others who had contributed to the theory.
In 1993, another Nobel Laureate Leon Lederman wrote a popular science book called The God Particle: If the Universe Is the Answer, What Is the Question? Incidentally, Lederman reportedly wanted the title to be “The Goddamn particle”, but the publishers, understandably, rejected the idea! However, when the Higgs particle was discovered, the press dubbed it the “God Particle”, a moniker which still raises hackles among particle physicists. This is also ironic given that Peter Higgs was an atheist!
More than a decade after its discovery, there are still many unanswered questions about the properties of the Higgs boson and its interactions. There are plans to build an accelerator, colloquially called the “Higgs factory”, which will hopefully shed some light on the still mysterious particle which Peter Higgs in his characteristic modest fashion would refer to as “the boson that is named after me”!
Shobhit Mahajan teaches physics at Delhi University. The views expressed are personal
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