books44 Chapter 417 - 215 Zhang Collision! (6.8K)_2
Chapter 417 - 215 Zhang Collision! (6.8K)_2
Currently, the Super-Kamiokande Detector over in Neon is specifically used for researching these particles. We also have a lab at Daya Bay domestically, which is acknowledged as one of Huaxia’s most important achievements in fundamental physics.
Every student who was shot by Hou Yi in their past life should know this.
The mystery of the disappearing solar neutrinos once puzzled the physics community.
To put it simply, scientists found that the flow of neutrinos produced by the Sun was only about a third of the theoretical model.
This mystery lasted for many years. Later, the scientific community discovered that there are actually three types of neutrinos.
They can transform into each other, a process called "neutrino oscillation."
The conversion modes of the first two types were experimentally verified one after another, but the probability of the third type of conversion... known as θ13, is very low, making it the hardest to detect.
The θ13 component contains a term in the Lagrangian that breaks CP symmetry, and the value is extremely close to that of a mysterious particle.
In other words,
from the characteristics of that mysterious particle today, it seems to possess some properties of neutrinos?
Of course.
Some student like Xian Weiren might be confused at this point.
Don’t worry.
Just continue reading.
Meanwhile, Zhao Zhengguo and others also discovered.
Besides having a term in the Lagrangian that highly suggests CP symmetry breaking, this particle’s orbital position is also a bit off.
The particle orbit of the 4685Λ hyperon is a standard 4f orbital, which can be described with seven functional equations.
According to the Pauli Exclusion Principle,
the multi-electron wave function must be exchange antisymmetric.
But Zhao Zhengguo and others, after simplifying the total Hamiltonian using adiabatic approximation and mean-field approximation, found that...
the multi-body system electron wave function of the unknown particle does not conform to the central field approximation of the Λ hyperon.
In other words...
this particle seems like a bizarre new particle that appears to be a Λ hyperon, but is somehow different!
But if it’s a new particle, another problem emerges:
Previously mentioned,
the four fundamental forces of Nature are the Strong Nuclear Force, Weak Nuclear Force, Electromagnetic Force, and Gravity respectively.
Among them, gravitational interaction is the weakest of the four basic interactions, yet its range is virtually infinite.
This is known as a long-range force.
Electromagnetic force exists between charges, is quite strong, and also acts over an infinite range.
Strong interaction acts between atomic nuclei, being the strongest of the four fundamental forces.
Its range is the second shortest among the four fundamental forces, classified as a short-range force.
The range is approximately 10^-15 meters.
Finally, there is the weak interaction, commonly known as the Weak Nuclear Force.
It, too, is a force existing within the atomic nucleus and is a type of short-range force.
The range is about 10^-18 meters.
Zhao Zhengguo and his team discovered, after calculating according to the band theory model, a very peculiar situation:
the distance between the new particle and the 4685Λ hyperon is approximately 10^-17 meters!
What does this mean?
It means that within such a distance, only the same type of particle theoretically won’t collide.
Taking our Earth as an example.
Everyone knows the Moon is Earth’s satellite (Ignoring the concept of co-orbits).
So, after long-term observation, we’ve concluded a ’rule’:
In the universe, small celestial bodies that form stable structures at close distances to large celestial bodies must have connected satellite systems.
This means that only a satellite can stably exist in the Moon’s position, not planet-like Venus or Jupiter.
In the microscopic domain, this Earth corresponds to the 4685Λ hyperon, and the new particle is akin to the Moon.
Therefore, at first, Xu Yun regarded the new particle as a ’satellite’ of the Λ hyperon, perhaps a new Λ hyperon with slightly less mass.
But as research deepened, Zhao Zhengguo suddenly discovered...
that new particle isn’t a satellite of the Λ hyperon at all; in fact, it is a planet similar to or even larger than "Earth."
On the other hand, however,
it can stay in the Moon’s orbit and form a celestial combination with Earth, without affecting each other.
This is indeed very intriguing...
Therefore, combined with the previously mentioned case of suspected CP symmetry breaking,
Zhao Zhengguo immediately thought of a concept:
Quantum tunneling!
Quantum tunneling refers to the quantum behavior wherein microscopic particles like electrons can penetrate or traverse potential barriers that exceed the particle’s total energy.
The most common place for quantum tunneling is in the nuclear fusion reactions of the Sun.
Although gravity compresses the material inside a star and serves as the ultimate energy source for nuclear fusion, radiating light and heat,
in reality,
the density inside stars isn’t too high, definitely not reaching the level of white dwarfs.
And clearly, the density of white dwarfs... in other words, the distance between two atoms, is still some way from undergoing nuclear fusion.
Because the core’s high temperature allows two atoms to collide at very high relative speeds, yet order-of-magnitude analysis shows that this relative speed is not sufficient for two atoms to overcome the Coulomb barrier.
To reach the embrace of another atom by breaking through the blockage of Coulomb forces, requires speeds hundreds of times higher than the temperature at the Sun’s core.
This calculation is easy to perform, and the relevant concept is usually mentioned in the second year of a Master’s program.
Namely, U~e^2/4πεr, where r is the atomic radius.