This is the best theory of understanding the nature or reality of the universe. Because, it explains the whole universe by combining two great theories – quantum mechanics and field theory. But, before reading this, I highly recommend to read the Standard Model of Particle Physics and Theory of Everything, because it will help you to understand the behaviours and nature of the particles.
Quantum field theory is the combination of quantum mechanics and field theory, hence the name. But what are these theories?
We already discussed about the basics of quantum mechanics in the previous articles. It is a part of modern physics which studies the behaviour of particles, atoms or molecules. It studies the whole universe in a smaller scale. According to modern physics, the reality is not what we observe. The actual reality is that, which is shown by quantum mechanics. That is why, the physicists are trying to solve every questions for the universe with the help of quantum mechanics. Standard Model of Particle Physics is the best example of studying the universe in quantum level. But due to excluding the gravitational force, a new theory was proposed in which gravitational force was also explained in quantum level which was named as Quantum Gravity.
Now, what is field theory? According to modern physics, the free space in the universe is consists of some fields. Normally, we think that the free spaces are completely empty. But it is not actually true. The free spaces are consists of some invisible fields. For example, there is free space between earth and moon, then is it really empty? If it is really empty, then how is it possible for moon to orbit the earth? Actually, between them, gravitational field is there, which helps the moon to orbit the earth. Like that, near two magnets, there is a magnetic field which apply some forces on the magnets. This is the reason why two opposite poles attract each other while two same poles repulse each other. We cannot see them, but that does not mean that they do not exist.
Now, if we combine the two theories then it will become Quantum field theory. This theory states that, in every particular position, there are many invisible fields in this universe. In fact, even all particles have also its own field. Like, magnetic field, gravitational field, electron field, proton field, Higgs field, gluon field etc. After applying energies on the fields, we get particles according to the fields. For example, after applying energy on quark field, we get quarks. Like that, by applying energy on electron field, electrons can be produced. But actually, the amount of energy applied on the fields depends on the mass of the particle.
Earlier, when the particles were discovered, then all the particles were divided by the Standard Model of Particle Physics depending on their behaviours. After conducting mathematical experiments, scientists found that, not only particles, but also quarks have its own mass. But, if quarks are the smallest particles, then they should be massless. But, they are not massless, they have also some masses. But how is this possible? What are the reasons behind the mass of the particles?
At that time, a British Theoretical Physicist Peter Higgs proposed a theory that, like other fields (electron filed, quark field etc) there is also an invisible field and this field exists everywhere in the universe. This field was later named as Higgs field. After applying energy on the Higgs field, a kind of particle is created which was named as Higgs boson. According to Peter Higgs, actually all elementary particles are massless. But, after entering in the Higgs field, some particles gain mass by interacting to it. For example, the electrons are also massless in nature, but due to Higgs field, electrons gain some masses by interacting to it. Hence the mass of electron is 9.10938356 × 10-31 kilograms. Like that, proton, neutron etc have also mass due to interaction with the Higgs field. But photons, gluons are massless, because they do not interact with the Higgs field. Simply. Higgs field provides mass to the particles.
Higgs Boson (The God Particle):
The actual name of God Particle is the Higgs Boson. Peter Higgs described in his theory that, Higgs Boson can be generated by applying energy on the Higgs field. At that time, physicists could not imagine about such types of field and particles, that is why his theory was rejected. But after, some physicists showed a little interest on his theory and the theory was proved with the mathematical equations several times. With the mathematical equations, physicists proved that, if Higgs field really exists, then we should get Higgs Boson by applying energy on this field. Again, the Higgs Bosons are quite heavy compared to the other particles, that is why it needs high energy to create Higgs Boson. This is possible only by colliding two particles in a very high-speed.
On 10 september, 2008, CERN (Conseil Européen pour la Recherche Nucléaire which means The European Organization for Nuclear Research) started to build the world’s most powerful and largest particle accelerator – Large Hadron Collider (LHC). In that particle accelerator, the charged particles were made to collide each other in the speed of 99.9% of speed of light. For a long time, scientists could not find any particles, but on 4 July, 2012, CERN announced that they have detected a particle with the help of LHC. That means, that high collision of charged particles apply external energy in the Higgs field which gave birth a particle. That particle is the Higgs Boson. This particle was later named as The God Particle.
This experiment not only proved quantum field theory but also proved that the theory of Peter Higgs was correct and Higgs field exist everywhere. The God Particle born when high energy is applied on the Higgs field. That is why, Peter Higgs and François Englert was awarded with Nobel prize in Physics on 8 october, 2013.
Properties of Higgs field:
Here are some of the properties of Higgs field.
1. Higgs field gives mass to the elementary particles which is referred as Higgs Effect .
2. Without Higgs field, every elementary particles would be massless and hence they could travel faster than the speed of light. Then the formation of atoms, molecules, quarks, leptons etc would never be possible and hence, matter could never be exist.
3. Unlike other fields like gravitational field, magnetic field, electric field etc, the effects of Higgs field always same in every position in the universe.
Properties of Higgs Boson (God Particle):
Here are some properties of Higgs Boson.
1. Higgs Boson can be created by applying high energy on the Higgs field.
2. Higgs Boson has zero spin value.
3. Higgs Boson decays immediately to another particle after its creation.
4. The mass of Higgs Boson is almost 125 Mev which is quite heavy compared to the other bosons.
So, these are some of the properties of Higgs field and Higgs Boson. But, there are still some questions which have not been solved yet like, dark matter, dark energy, the actual size of Higgs Boson etc. However, scientists are now studying these particles which may reveal the existence of the universe in the distant future.