The particle physics community is all abuzz: on Tuesday, the CERN Council reported encouraging data in the search for what has been called the “Holy Grail of high-energy physics” — finding the hypothetical particle called the Higgs-boson particle. Also called the “God Particle,” it is the last of the fundamental particles predicted by quantum mechanics to be confirmed experimentally.
CERN: The Ultimate Atom Smasher
Deep below the pastureland and vineyards along the Swiss-French border outside Geneva is the Large Hadron Collider, the world’s largest particle accelerator. At this CERN site, charged particles scream through a 17-mile ring-shaped subterranean tunnel. Accelerated by large electric fields and steered by super-cooled magnets along tunnel walls, these particles circle faster and faster, approaching near light-speed. Then, in the ultimate demolition derby, they smash headlong into pre-arranged targets.
The resulting high-energy collisions produce a spray of new subatomic particles that scatter in all directions. State-of-the-art detectors up to several stories tall record the results. Particle physicists then pore over the data traces, looking for the slightest bits of evidence for the missing link of quantum mechanics — the Higgs boson.
The Higgs Field and the Higgs Boson
The so-called Standard Model of quantum mechanics describes how the universe works on the smallest of scales. It is the most accurate physics theory in history. But what gives mass to the sub-atomic particles predicted by quantum theory — such as quarks which make up protons and neutrons, and electrons and neutrinos?
In 1964, three groups of physicists independently proposed an answer: the Higgs field — named after one of the researchers, English physicist Peter Higgs.
The scientists proposed that the Higgs field formed just after the big bang and now permeates our entire universe. However, its strength in empty space is not zero. It is as though the vacuum of space contains an an invisible field of molasses, affecting the movement of the basic building blocks of matter.
Per the Higgs Field theory, the more strongly a particle interacts with the Higgs field, the more massive it becomes. Some particles, like photons (particles of light) do not interact with the Higgs field at all, so remain massless. As particle physicist Pippa Wells points out, without the Higgs field, all particles would “wizz around the universe at the speed of light.”
Several years later, physicists Steven Weinberg applied the Higgs theory to the weak nuclear force which is responsible for radioactivity. From this work, he predicted the existence of the “Higgs boson” — the messenger particle of the Higgs field. (Just as photons are the messenger particle of electromagnetic fields.) And the hunt for this elusive particle was on.
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