Is the greatest hunt in modern science over? Scientists from two research teams, working independently of each other, have announced the results of an atom-smashing experiment in Switzerland where the Large Hadron Collider (LHC) at CERN may have finally found one of the most sought-after elementary particles: the Higgs boson.
Ever since Peter Higgs first identified the particle in 1964 as a by-product of the mass-giving field, the standard model of particle physics has considered the Higgs boson as the ultimate particle that explains why all the others have mass. Although Albert Einstein explained gravity, he couldn't find out why things have mass in the first place. Higgs showed how a field that clings to particles produces their mass, making them heavy. Particles of light are oblivious to this, while others wade through it like we do on flooded Delhi roads during the monsoons. In other words, particles can weigh nothing, but as soon as they are in the Higgs boson field, they become heavy. Hence the Higgs boson's nickname, 'God particle', as it gives mass to all matter. In that sense, the Higgs boson is actually hiding in plain sight - an enigma right in front of our eyes, as it gives all matter its mass.
For all its elusiveness, however, we know the ghostly Higgs has a tell-tale signature: it gives rise to a field that interacts with all other subatomic particles. During such interaction, these particles experience a drag that depends on their mass. So physicists hit upon the idea of slamming atoms at each other at high enough energies so that the Higgs would eventually be forced to reveal its 'tracks' in the resulting sub-atomic rubble. At least that is the theory. Technically, though, this is far more difficult than looking for that proverbial needle in a haystack for the Higgs is so unstable that it decays instantly, and can be detected only once in every ten trillion collisions. Hence the need for super-energetic colliders and highly sensitive detectors such as the LHC. The LHC occupies a 27 km super tunnel that crosses the Franco-Swiss border, in which proton beams are shot at over 99% of the speed of light in two parallel beams in opposite directions so that they crash into each other to create the mother of all experiments. Scientists hope the collisions occurring inside the giant machines will recreate the same conditions that existed in the first trillionth of a second after the big bang. And help track down the Higgs boson.
These are early days yet to say with any degree of certainty whether the Higgs has indeed been spotted. But the researchers owe their optimism to the fact that they are statistically able to rule out false alarms after a large number of collisions. Many more experiments and clarifications would be needed before the discovery is formally confirmed. But if and when that happens, it will literally revolutionise the way we look at the world around us. For finding Higgs will answer some of the most brain-bruising questions before science: what gives matter mass? What is the nature of dark matter and dark energy that account for 96% of the universe? How did the universe begin, and how will it evolve? The discovery could also help unify the four fundamental forces of nature: the strong and weak nuclear forces, gravity, and electromagnetic forces. And we will then know for sure whether, as string theorists believe, space-time holds dimensions other than our own.
Prakash Chandra is a senior journalist
The views expressed by the author are personal