Chapter 201 A brand new particle track (5.6K)
Mentioned previously.
in microphysics.
Elementary particles can be divided into four categories:
Quarks, leptons, gauge bosons, and Higgs particles.
And quarks cannot exist alone due to the static confinement of quarks.
Therefore, in the microscopic realm, quarks mainly exist in pairs and three:
For example, a positive quark and an antiquark form a meson.
Or three quarks or three antiquarks make up a baryon.
Baryons and mesons are collectively called hadrons. For example, the protons and neutrons we are familiar with belong to baryons.
Other than that.
Hyperons are also a type of baryon.
What's special about it is that it contains at least one strange quark, which allows us to understand how baryons interact by studying hyperons.
There are many types of hyperons discovered so far.
For example, Σ-hyperons, Ξ-hyperons, Ω-hyperons, etc.
That's right.
Presumably some students have already remembered it.
In "Handbook of Conquest of Different Worlds", the particle beam used by the rabbits to blast open the secret realm of Qingcheng Mountain Tiangong is Omega-hyperon.
The Λ hyperons observed by Academician Zhao Zhengguo not long ago also fall into the above category.
See here.
Many people may be confused:
Although these contents seem easy to understand, what is the specific meaning of Λ hyperon?
The theoretical significance of Λ hyperons is actually many.
For example, it may help discover the legendary fifth force.
For example, it is helpful for the detection of dark matter and dark energy.
It can even study neutron stars and so on.
And in reality.
The most direct impact is on the mobile phones you and I use.
At present, all mobile phones use the knowledge of quantum theory, because most of the core components of mobile phones use semiconductors, and the performance of semiconductor materials must be calculated and optimized based on quantum mechanics.
For example, there is a gap in the PN junction.
According to popular understanding, the electric potential energy is greater than the kinetic energy of the electron. Under normal understanding, it is impossible for the electron to pass through this gap.
However, under the scope of quantum mechanics, electrons are allowed to transition with a certain probability. This phenomenon is called electron tunneling.
Electron tunneling microscopy utilizes this principle. You can see the potential energy fluctuations on the surface of the material.
Then infer the surface structure of the material, and finally conduct semiconductor research and development.
For example, Samsung has already sold a mobile phone called Galaxy AQuantum equipped with an optical quantum chip, which only cost more than 500 dollars. Unfortunately, it has not exploded.
Optical quantum chips are used to generate quantum random numbers to ensure that encryption algorithms are physically absolutely safe. This is also a trend in the future.
Therefore, microscopic particle research is actually closely related to our reality, but because the final product is a complete state, there are certain information barriers for many of the technologies involved.
And compared to other superons.
Λ hyperons are even more special.
It is a very special type of hyperon, and its single-particle potential well depth in nuclear matter is the deepest among all known particles.
To put it in a more informal way, the person’s words are wrong.
It can be regarded as a very critical foundation in controllable nuclear fusion.
Therefore, all countries currently attach great importance to it, and the relevant annual expenditures of several leading countries start at 100 million to 200 million.
The eyes are returning to their original position.
Academician Zhao and Xu Yun had heard about this observation. The maximum polarization degree of the decay event exceeded 26%, which is the first time in the world.
It's not a big news.
But be aware.
Before Academician Zhao and his colleagues made the first breakthrough, the maximum polarization degree in the world had reached 25%.
Therefore, the conceptual significance of their first breakthrough was greater than the actual significance, and they could only lead by half a body.
But now the formula in Xu Yun's hand seems to be pointing to another track:
Don't forget.
The similar binding energy figures between the two are actually the result of Xu Yun changing y(xn+1) to y(xn+2).
In other words.
On the orbit y(xn+1).
Theoretically, there is another Λ hyperon with a different magnitude.
Think of this.
Xu Yun's curiosity became more and more intense.
Then he switched to the Aurora system again and entered the number of 4685Λ hyperon.
After a while.
A bunch of decay case samples appeared in front of him.
Unlike other research, particulate information does not require too much consideration for confidentiality.
Because there is a big difference between front-end particle research and modern technology, it is difficult to directly expand the discovery of a certain particle into a certain technology, and there is not much confidentiality value.
Therefore, after discovering new particles or related information, the discoverers will basically disclose all the information openly.
There are 37 decay samples uploaded by Academician Zhao Zhengguo, divided into six files.
There are a lot of decay parameters marked in it, plus some other little-known data that looks like astronomical figures, but is actually very important.
The observation method of Λ hyperons is particle collision. When talking about particle collision, the first reaction in many people's minds are particularly powerful words such as "tens of billions" and "high-precision".
But if you want to say what the particle collider is used for, many people may not be able to tell.
In fact, the principle of this thing is very simple:
You want to study an orange, but you have fingers as thick as a building.
You feel it, but you don't see it.
You want to crush it, but you find that it is always cunningly hidden in the gaps between your fingers.
It's so small that you can't even touch it, let alone peel it off.
Until one day you suddenly have an idea and use a pile of oranges to hit another pile of oranges.
Ever since.
Bang!
They shattered.
You feel the pith, the juice, the peel.
Ever since.
You know what an orange looks like, with an orange core, juice, and orange peel.
This is actually the nature of a collider.
In the microscopic realm, the orange juice turns into various charged or uncharged particles.
If you want to separate them, you have to expend a certain amount of energy - the force of the collision of two large bags of oranges.
So how much energy does it take to separate the components of matter at different scales?
The force between molecules is the smallest, with an average of less than 0.1eV - eV is electron volts, which refers to the energy change caused by an electron charge passing a voltage of one volt.
This is a very small unit, and its effect on the human body may be equivalent to being pricked by Fanfan.
Chemical bonds are higher.
Between 0.1-10eV.
The inner electrons are probably several to tens of KeV.
Nucleons are above MeV.
The deepest currently is quark:
The energy level between quarks is tens of GeV.
Calculated according to Brother Donkey’s worksheet, this energy level is almost as long as Pikachu has been generating electricity since Wu Zetian ascended the throne to now
And what were Zhao Zhengguo and the others observing?
Again, take orange juice as an example.
After two oranges collide, the splash area and image of orange juice are unpredictable and completely random.
Some orange juice splashes are better, some are worse, and some are even more difficult to observe.
Therefore, it is actually very difficult to observe a new particle. You have to look for it one by one with a magnifying glass, just to look at the face.
But it's another thing if you can know its trajectory in advance.
For example, we know that a drop of orange juice will splash on the ground seven meters away at an angle of 37 degrees southeast of the collision site. This ground originally had a lot of sewage sludge, and the splashed orange juice will be mixed together and cannot be observed.
But we already know its trajectory in advance, so we can put a clean sampling plate there in advance.
Then leave the scene with your hands, find a chair to prepare, and wait quietly for it to be delivered to your door.
Now that we have the information about Λ hyperons and the formula model, the process of deriving the "falling point" is very simple.
As everyone knows.
The general solution to N and decay is not complicated.
For example, there is a decay chain A→B→C→D..., and the decay constants of various nuclides are λ, λ, λ, λ... respectively.
Assuming that there is only A at the initial time t, it is obvious that: N=N(0)exp(-λt).
Xu Yun then wrote another equation:
dN/dt=λN-λN.
This is the differential equation of the change in the number of B atoms.
The solution can be obtained as N=λN(0)[exp(-λt)-exp(-λt)]/(λ-λ).
Then Xu Yun read while writing:
"The differential equation of the change of C atomic nucleus is: dN/dt=λN-λN, that is, dN/dt+λN=λN."
"Put in the N above, so it is N=λλN(0){exp(-λt)/[(λ-λ)(λ-λ)+exp(-λt)/[(λ-λ)(λ-λ) ]+exp(-λt)/[(λ-λ)(λ-λ)]｝.”
After writing this, he paused and did a simple calculation.
After confirming that there is no problem, continue writing:
"A parameter h can be defined such that h=λλ/[(λ-λ)(λ-λ)], h=λλ/[(λ-λ)(λ-λ)], h=λλ/[(λ- λ)(λ-λ)]"
"Then N can be simplified as: N=N(0)[hexp(-λt)+hexp(-λt)+hexp(-λt)]."
Finish writing these.
Xu Yun looked at the screen again and substituted the parameters of the Λ hyperon:
"N=N(0)[hexp(-λt)+hexp(-λt)+...hnexp(-λnt)], the molecule of h is Πλi, i=1～n-1, that is, the molecule is λλλλ."< br>
"The decay period of the Λ hyperon is 17, so the denominator of h is the product of the difference between the decay constant of the Λ hyperon and the Λ hyperon decay constant λ."
Half an hour later.
A set of numerical values is realized on the Aurora software.
aa01000：
1904.8374
2818.7308
3740.8182
7496.5853
8449.329
Xu Yun didn't look at the numbers in front and quickly pulled down the mouse.
Soon, he locked on the eighteenth line:
18165.2989.
With this set of numbers, the next question is very simple.
Xu Yun entered this number into the aurora model, and the formula is:
F(t):=N(t)/N(0)=e^(-t/π).
The ":=" here is a definition symbol, which means defining the thing on the right as the thing on the left.
Xu Yun now gives this F(t) a physical meaning:
The probability that an atom is still alive (not decayed) at time t.
N=N(0)[hexp(-λt)+hexp(-λt)+...hnexp(-λnt)] This formula describes how many atoms are left at time t. What Xu Yun did was to add the number of remaining atoms Compared with the initial total number of atoms, this quantity is naturally the probability of finding the one Xu Yun wants among the remaining atoms.
Very simple and easy to understand.
The Aurora system is connected to the secondary server of the Chinese Academy of Sciences and uses part of the computing power of the Chinese Academy of Sciences' supercomputer "Yeyu".
So only more than ten minutes passed.
A result was displayed on the screen in front of him:
t=0, F=1.
See this situation.
Xu Yun's pupils suddenly shrank slightly.
This result means.
At the beginning, there was a particle in the orbit y(xn+1)y(xn)/h≈f.
It was just that its lifespan ended or its transition was disabled during the impact, so it was not captured in the end.
Think of this.
Xu Yun was silent for a moment and walked out of the library.
He took out his cell phone and dialed a number.
After a while.
The phone was connected, and a voice that was instantly handsome came from the other end:
"Hello, Xiao Xu?"
"Well, it's me. Teacher, are you free now?"
"Just got out of the laboratory, what's going on?"
Xu Yun organized some words and said:
"Teacher, didn't I study a topic on Σ hyperons before? Do you still remember?"
Σ hyperon is one of the more mainstream hyperons at present, with a lifespan of 0.15 nanoseconds and a slightly heavier mass than a hyperon.
Xu Yun's master's degree topic is the impact of energy levels generated under the strong interaction of Σ hyperons, which involves some theoretical fields of quantum chromodynamics.
So it's quick.
Academician Pan’s reply came from the other end of the phone:
"That's right, oh, I saw your record of turning on the Aurora System. Has your research yielded results?"
Aurora involves the computing power of the server, and each student's share is limited.
As Xu Yun's mentor, Academician Pan will naturally receive relevant notifications, and Xu Yun has no intention of hiding it from him:
"It's like this, teacher. When I was studying Σ hyperons, I suddenly discovered a relatively special phase orbit. The eigenstates are somewhat different from Σ hyperons."
"Later, I used the auroral system to conduct simulations and found that it was somewhat similar to the 4685Λ hyperon observed by Academician Zhao not long ago."
"So I performed an optimized simulation on this orbital formula, replaced the Σ hyperon with the decay parameters of the Λ hyperon, and finally found."
Opposite the phone.
Academician Pan was originally tilting his head, holding his mobile phone between his shoulders and ears, while his hands were disassembling a takeaway takeaway of saury.
But when I heard Xu Yun's first words.
He vaguely realized something and stopped what he was doing.
When Xu Yun finished speaking the last sentence, his expression became much more solemn, and he completely followed Xu Yun's thoughts:
"Xiao Xu, what's the last F?"
"t=0, F=1, in other words, there should be a new particle in that orbit."
After speaking, Xu Yun paused and added:
"A new particle that can be captured and observed." (End of Chapter)