Chapter 525: The Road to Grand Unified Theory (Please Subscribe!)

Chapter 525 The Road to Grand Unified Theory (Please subscribe ⊙⊙!)

What role does the Higgs mechanism play in the process of weak interaction separation?

As we all know, the so-called Higgs mechanism is actually an important theory in the standard model. It explains why some elementary particles have mass while some particles do not. It is a mechanism for giving particles mass.

This mechanism involves a field called the Higgs field, which is ubiquitous in the universe. It gives particles mass through spontaneous symmetry breaking.

And from the gauge field theory, including the Yang-Mills theory, it is derived that if you want to unify the electroweak force under the framework of the gauge field theory, you must assume that the W and Z bosons are initially massless, and their mass is given by acquired factors.

This is the well-known Higgs mechanism.

The process from no mass to mass is the process of symmetry breaking.

After the three propagators of weak force, positive and negative W bosons and Z bosons have mass, their range of action cannot even break through the nucleus, making the weak interaction force completely become a short-range force.

Its range of action is only 10 to the negative 18th power of meters, which is one thousandth of the length of a proton. However, the electromagnetic force is a long-range force, and its propagator photon mass is zero.

In other words, as long as the mass of the propagator of the weak force is also zero, its manifestation will become a long-range force like the electromagnetic force, which is the moment of unification of the electroweak force.

So under what circumstances can the mass of the propagator of the weak force be zero? The answer is obvious, that is, when the symmetry of the gauge field theory is not broken. If the symmetry of the Higgs field is not broken, the Higgs mechanism will not take effect, and the propagator of the weak force will not gain mass.

The key factor of symmetry breaking depends on temperature.

As long as the temperature is high enough, the Higgs mechanism will fail, symmetry breaking will not occur, W and Z bosons will not gain mass, and the electromagnetic force and the weak interaction force will be exactly the same in manifestation. At this time, the propagator speed of the weak interaction force will also become the speed of light, and like the electromagnetic force, it will be transmitted infinitely in the universe.

The standard particle model predicts that the critical temperature at which the Higgs mechanism fails, that is, the energy level at which the electromagnetic force and the weak interaction force are unified into one force, is 100 GeV.

Human particle colliders have the ability to collide with this energy level, so they really simulate the unification of the electromagnetic force and the weak interaction force, and thus successfully unify the two forces.

And now, Liu Miyan means to continue to use the idea of ​​the standard model to unify the strong interaction force, and the three forces become one force, so that humans can turn the grand unified theory into reality and become a theory mastered by humans like the electroweak theory.

So how to unify the strong interaction!

First of all, we have to understand what kind of force the strong interaction force is. The strong force is responsible for binding the protons and neutrons in the nucleus together. In any nucleus, all protons are positively charged. If there is no strong force to bind them, they will be repelled by the electromagnetic force, causing the nucleus to break.

In other words, it is the strong force that overcomes the repulsive force between protons and binds them in the nucleus.

This phenomenon explains why there are only about 100 known elements in nature. That is because after the number of protons in the nucleus exceeds 100, the repulsion between them is difficult to contain even with strong force.

The propagator of strong force is gluon. Unlike the propagator of weak force, its mass is zero, so its speed is the speed of light, which is the same as the propagator of electromagnetic force. The difference is that the strong force propagator gluon is locked between quarks and cannot escape.

This is the so-called quark confinement. The farther the distance between quarks, the stronger the strong interaction force, and the closer the distance, the weaker it is. Therefore, the closer the distance between quarks, the freer they are. This phenomenon is called asymptotic freedom.

So from here we can see that if we want to unify the strong interaction force, we have to let its propagator break through the quark level and become a long-range force like electromagnetic force.

According to this idea, we must find a way to let the strong force propagator break through the quark level. So how can we let the strong force propagator break through the quark level?

The answer is still temperature.

The standard model infers that when the ambient energy is above 10 to the 15th power GeV, quarks will not be bound by gluons, quark confinement and asymptotic freedom will disappear, and gluons can rush out of atoms at the speed of light, so that the strong force becomes a long-range force.

In this case, scientists can collect various data, and then complete the unification of strong forces according to the method of improving scientific theories, so that humans can master the grand unified theory.

Of course, in this case, atoms will not exist.

So why do we know that the energy value of 10 to the 15th power GeV is the critical point?

This goes back to what I said before, that the universe is not divided into up and down, front and back, but left and right, and of course quantum chromodynamics.

When humans, based on the concept of miracles with great force, use violence to forcibly smash protons and neutrons and even blast quarks apart, they find that after the quark pairs are knocked apart, the energy that makes the quarks apart is exactly the energy required for the formation of new quarks.

So, as soon as the quarks were knocked apart, the energies instantly formed new positive and negative quark pairs, and the color charge of these two new positive and negative quark combinations happened to be white. This is because quantum chromodynamics stipulates that the total color charge of quarks can only be white, that is, the color charge.

So, the gluon transmits strong force in the new positive and antiquark pairs.

It is like hitting a lonely place.

Of course, it is not completely lonely. At least this phenomenon also makes scientists notice that positive and antiquark pairs do not annihilate.

In people's cognition, positive and antimatter will definitely annihilate when they are together, and this is also true, but positive and antiquark pairs are stuck together and do not annihilate.

This is magical.

For such a phenomenon, humans must find a way to figure out why. In fact, with the efforts of countless scientists, the reason has been figured out.

That is chiral symmetry.

Scientists have found that as long as positive quarks and antiquarks have chiral symmetry, that is, chiral symmetry holds, they will annihilate.

On the contrary, if chiral symmetry is destroyed, they will not annihilate. Then according to quantum chromodynamics, we know that because the gluon color charge needs to be, positive and antiquarks will gather together, and the energy that gathers them together is the binding energy between quarks.

The universe is not divided into up and down, front and back, but left and right, which is so magical.

This process is called spontaneous chiral symmetry breaking. The binding energy generated by this phenomenon constitutes 99% of the mass of protons and neutrons. Yes, the binding energy at the quark level is manifested as the mass of protons and neutrons.

This is the source of the mass of everything we see in daily life.

Now it is obvious that Liu Miyan's goal is to obtain a more powerful collider so that humans can collide with 10 to the 15th power GeV energy level in the laboratory, recreate the environment when the chiral symmetry was not broken at the time of the Big Bang, and then study what it is like when the strong force or the long-range force is combined, what it is like when the three forces are combined, what are the specific physical manifestations, etc.

In this way, we can explore and master the grand unified theory.

Science is an experimental-based discipline. Without experiments and data, there will be no progress. The threshold of the laws of the universe is not so low that it can be mastered by my thinking alone.

Yu Nanfeng knew all this, so he understood Liu Miyan's demands, and for this reason, he didn't know what to say at the moment. He also wants to say that humans can build such a collider, and he is also willing to see humans have a more powerful collider, but the actual technological strength does not allow it!