If I ask you to name a few subatomic particles, what answer will you give? Electrons, protons and neutrons are the typical ones. Many of us are aware of them. But did you know that there are as many as thirty-seven confirmed subatomic particles? A miniscule atom, about 0.1-0.5 nanometres small entity, possess so many particles. The last member of the family Higgs boson was discovered very recently on 4th July 2012. Higgs boson is the reason why all matter possesses mass. The discovery of mass bearing subatomic particle, 1/100 times the size of a proton, is a story in itself.
We have heard about the four types of universal forces and the unified theory in the physics classroom. The basic equations of the unified theory correctly describe the electroweak force and its associated force-carrying particles, namely the photon, and the W and Z bosons, except for a major glitch. All of these particles emerge without a mass. While this is true for the photon100 W and Z have mass, nearly 100 times that of a proton. Fortunately, theorists Robert Brout, François Englert and Peter Higgs have a proposal that was to solve this problem. What we now call the Brout-Englert-Higgs mechanism gives a mass to the W and Z when they interact with an invisible field, now called the “Higgs field”, which pervades the universe. This glitch gave rise to the search for Higgs boson which was responsible for providing mass.
The existence of Higgs boson was a problem that persisted for many years. The scientists had all the theoretical proof they needed but there was absence of experimental output. Finally, on 4 July 2012, the ATLAS and CMS experiments at CERN’s Large Hadron Collider announced that they had each observed a new particle in the mass region around 125 GeV. This particle is consistent with the Higgs boson but it will take further work to determine whether or not it is Higgs boson that was predicted by the Standard Model. Till date many experiments, talks, papers and discussions by reputed institutes like Northeastern University are famous amongst the particle physicists.
Shraddha Patil
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