In 1964 peter Higgs with five scientists proposed a theory called the Higgs mechanism to explain the existence of mass in the universe. Before 1930s, atoms were considered as the fundamental particles. Then we found electron, protons and neutrons as atomic particles. Later we found that protons and neutrons are made up of even more small fundamental particles called quarks. Quarks are the fundamental building blocks for the whole universe. The key evidence for the existence of these elementary particles came from a series of inelastic electron-nucleon scattering experiments conducted between 1967 and 1973 at the Stanford linear accelerator center. They are commonly found in protons and neutrons. There are six types of quarks, up quark, down quark, top quark, bottom quark, strange quark, charm quark. They can have positive (+) or negative (-) electric charge. Up, charm and top quarks have a positive 2/3 charge. Down, strange, bottom quarks have a negative 1/3 charge. So protons are positive because there are two quarks (+2/3) ups and one down quark (-1/3), giving a net positive charge (+2/3+2/3-1/3 =1). These three quarks are known as valence quarks, but the proton could have an additional up quark and anti-up quark pair.
The Higgs field theory
In the second half of the 20th century, physicists made a developed a theory called a standard model of particle physics. They theorized about twelve fundamental particles that make up all matter, and four particles called bosons are responsible for three fundamental forces of nature. It includes strong force, weak force, and electromagnetism. Gravity is another force, it is not a part of this model but, it can be modeled using general relativity. With these fundamental particles in the standard model and gravity, we can build almost everything in the entire universe. However until 2012, the standard model was an underlying theory. Because all forces carrying particles should be massless. So, although the photons are massless, experiments show that the weak forces bosons have mass. So that was a promising model that could be used to explain our universe. But perhaps, it would need to be thrown out because it had the seemingly fatal flaw in being inconsistent regarding the way the weak force worked in the late 1950s physicists had no idea to resolve these issues all attempts to solve this problem. But indeed it created new theoretical problems. In 1964, Peter Higgs hypothesized that perhaps the force articles were massless but gained mass when they interacted with an energy field that is the reason for the existence of the entire universe.
During the very early moments following the big bang, in the universe, the elementary particles were massless and they were pure streams of energy that move at the speed of light. As the expansion of the universe was proceeding, density and temperature decreased below a certain key value. According to the theory, the Higgs field interacts with particles and can give them mass. It is theorized that different particles interact differently with the field, the particles that interact with it more intensely have greater mass and particles that don’t interact with it that much have lower mass. Just imagine Higgs field as water, pointed shape objects interact lesser with water and cube shaped objects interact more with it. Some particles don’t interact with the field like photons are massless. A fundamental part of the theory was the presence of a specific particle; it’s called the Higgs boson. A boson that would allow the Higgs mechanism to unfold correctly to give mass to all other particles.
CERN’s discovery of a new particle
Even though Higgs theorized it, scientists can’t able to prove that until 2012. The particle accelerators had to possess a huge amount of energy to detect them. Finally, the Large Hadron Collider (LHC), the CERN’s particle accelerator has been turned on in 2008 and managed to recreate the required energy and temperature conditions in 2012. The Higgs boson was finally experimentally detected and on 4th July, a conference held in the CERN auditorium announced the discovery of a particle compatible with the Higgs boson. The machine accelerates Hadron bundles at close to the speed of light and collides them each other in opposite directions. At four separate points the two beams cross, causing protons to smash into each other at enormous energies, with their destruction being witnessed by super-sensitive instruments. Even if LHC is the world’s largest particle accelerator, it had to work hard to detect Higgs boson. If the Higgs field doesn’t exist, all particles in the universe will become absolutely weightless and fly around the universe in the speed of light. For This reason Higgs boson is often called as the ‘God particle’.
“I never expected this to happen in my lifetime and shall be asking my family to put champagne in the fridge.” – Peter Higgs