Higgs boson sequel will be released in Tamil Nadu hills

The discovery of the Higgs particle has got particle physicists excited in India too, especially those working on a giant neutrino detector being built inside a mountain near Madurai in Tamil Nadu. “The discovery has given us a lot of confidence. It shows that we are going in the right direction,” said Naba K Mondal, senior professor and spokesperson for the Neutrino Observatory (INO). The INO, to be commissioned by 2017, will enable scientists to go beyond the Standard Model, validated by the Higgs discovery.

The Standard Model, formulated in the early sixties, is a theory to explain the nature and behaviour of the fundamental particles that make up protons, neutrons and electrons, which in turn make up everything we see around us. It deals with the particles themselves (six quarks and six leptons) as well as the forces (four in all) that act on them. However, for this theory to work, an assumption had to be made that all these fundamental particles are without mass. This was however just not true, because observation showed that quarks did have mass. 

This is where Peter Higgs saved the day. He postulated that all particles are without mass until they interact with something called the Higgs Field; particles were massless when they were created at the Big Bang, but within a trillionth of a second, the Higgs Field spread throughout the universe and gave each particle its mass.

The so-called Higgs Boson is a particle of the Higgs Field, and so the discovery of a particle that closely resembles the Higgs Boson at the Large Hadron Collider (LHC) proves that the Higgs Field indeed exists, and that our understanding of the origins of the universe are at least partially correct.

However, there are other experiments and observations that expose holes in the Standard Model. For instance, dark matter, which constitutes the majority of our universe, is made up of entirely different particles. What led to the creation of these particles? Also, as per the Standard Model, one variety of leptons, named neutrinos, are supposed to be massless (even after interaction with the Higgs Field). However, previous experiments have suggested that neutrinos have very small masses. How do neutrinos get this mass?

It is this second question which the INO near Madurai will seek to answer. “It will take physics beyond the Standard Model. Other fundamental particles such as quarks have been studied to a far greater degree than neutrinos, which are small and hardly interact with any other particle,” said Mondal.

Most of the neutrinos on Earth come from the Sun. Neutrinos are also generated when cosmic rays from space interact with the Earth’s atmosphere. In fact, such atmospheric neutrinos were first detected by a team of physicists from India, Japan and the UK in the Kolar Gold Fields.

“Our underground neutrino lab in the Kolar Gold Fields first made that discovery. But experiments around neutrinos haven’t happened in India since the gold fields were closed. The INO will be our next major lab,” said Mondal.

That neutrinos are generated during radioactive decay also make for some unique practical applications. For example, if a country hides its nuclear reactor to evade detection under the non-proliferation treaty, the neutrinos escaping from the reactor will give the game away.

Theoretical physicists working in India too are excited by the implications of the Higgs Boson’s discovery. . “All the research I have done till date focuses on theories that can explain dark matter and dark energy. I have always assumed the existence of the Higgs Boson. Now I will be able to place specific values instead of approximations,” says Sreerup Raychaudhuri, associate professor at the Tata Institute of Fundamental Research.

Raychaudhuri’s colleague Amol Dighe is excited over the prospect of studying a particle that possibly isn’t the Higgs Boson even if it is similar to it. “I now have a starting point to do my research — I know for a fact that the mass of this particle is 125 times that of a proton,” says Dighe.

Clearly, many exciting new discoveries in particle physics await us in the years ahead with the confirmation that Higgs was right.