Institute of High Energy Physics.
"Xiao Guo, look at this part of the data, can you process it, and then look at the simulation situation."
In the computer room, the director of Institute of High Energy Physics, academician Tang Yifang, took out some data and handed it to Guo Ding in front of him.
"Okay, let me take a look..."
Guo Ding nodded, and after taking the data, he started to read it.
He has been away from Institute of Physics for a few days. He has lived in Institute of High Energy Physics these days, and his sleep is delicious and delicious.
No need to stay next to that stress monster Xiao Yi.
Hmm... Although Xiao Yi never says anything, he himself has an aura of pressure.
It's still comfortable here!
As for their project, it is mainly related to QCD phase transition.
QCD refers to Quantum Chromodynamics, which is a theory that can describe strong interactions. It mainly studies the behavior of quarks and gluons at the subatomic scale. In High Energy Physics, studying the QCD phase transition is an important part of understanding the early state of the universe and strong interactions.
The goal of this topic is to deeply study the properties of quark-gluon plasma and its phase transition process.
Quark-gluon plasma is a substance in an extreme state. In this state, quarks and gluons are no longer bound in hadrons such as protons and neutrons, but exist freely. As for such extreme conditions, in nature, they can only be formed under the conditions of the early Big Bang.
In non-nature, it can only be achieved through extremely high-energy heavy ion collision experiments.
Of course, since it is a phenomenon that can only be produced by the Big Bang, studying this issue can help scientists understand the state of the universe within a few microseconds after the Big Bang, thereby exploring the material state and evolution process of the early universe.
In addition, it can also help guide the verification and improvement of QCD theory, and can also provide analogies for phase transitions in other physical systems, such as superconducting mechanisms.
"Hmm... You have to use NS equation to conduct a fluid mechanics simulation."
After briefly looking at the data, Guo Ding said, "Then we may have to simulate the models of Lattice QCD, color charge and shielding effect, which will take a while."
"That's okay, as long as you can handle it."
Academician Tang said with a smile.
However, he did not leave immediately, but continued to ask curiously, "By the way, you were at Academician Pang some time ago, and were you doing research with Xiao Yi?"
"Yes." Guo Ding nodded.
Academician Tang sighed with emotion, "I heard that in the past two days, International Congress of Mathematicians announced their invitation list. Xiao Yi seems to have been invited to give a one-hour plenary report?"
"Yes." When talking about this matter, Guo Ding's expression fell. "He received the letter from International Mathematical Union in front of me."
"Oh?" Academician Tang became interested. "Elaborate."
Guo Ding shook his head helplessly, and then told Academician Tang what happened that day.
Tang Yifang laughed loudly, pointed at Guo Ding and started laughing and scolding, "You didn't work hard yourself, and now you want to drag Xiao Yi into the water? If people find out, I'm afraid you will be scolded."
Guo Ding: "I don't have any, please don't accuse me wrongly."
"I have wronged you. I don't know how many times I have told you this. Otherwise, you would probably be on the verge of being rated Outstanding Young Scholar, right?"
Tang Yifang shook his head and said, "Forget it, I'm too lazy to tell you so much."
"But having said that, according to what you just said, Xiao Yi achieved results on the first day he arrived at Academician Pang's place. So what do you think if you call him to our side?"
"Ah?" Guo Ding immediately said, "Are you looking for him again?"
"What? No?" Tang Yifang glanced at him. "It's just in time for someone to come over and encourage you. You are in your thirties and almost forty. Xiao Yi At your age, he would have probably taken two Outstanding Young Scholars."
Guo Ding The corners of his mouth suddenly twitched. Is this how the account was calculated?
He muttered, "Then at your age, you would probably have gotten three Outstanding Young Scholar..."
"What did you say?" Tang Yifang stared.
"No, no, no." Guo Ding said quickly, "I say you are right."
Tang Yifang snorted and said, "I'm too lazy to talk to you. Anyway, I've left the task in your hands."
"First, analyze these data. Second, find a way to shake Xiao Yi over. Do you understand?"
"I understand, I promise to complete the mission!"
Guo Ding stood at attention and quickly promised.
Tang Yifang pointed at him and then left.
The next day, Institute of Physics, National Research Center for Condensed Matter.
Xiao Yi had a pile of experimental data and experiment-related images in front of him for him to study.
These data and images reflect various conditions inside the material during the transition from the superconducting phase to the insulating parent phase of FeSe/SrTiO3.
Analysis of these data can help research on the mechanism of superconductivity, especially for such high-temperature superconductors.
Xiao Yi narrowed his eyes slightly.
"The change in iron vacancies obviously has a huge impact on the electronic state inside the material."
"Well... if you simply use the density of states method to calculate, you can also find this kind of problem."
"Computational simulation results in the past few days can also be concluded that iron vacancies will cause local electron density fluctuations, which will then lead to the transition from the superconducting state to the insulating state by changing the interaction between electrons and the energy band structure."
"Especially according to spectroscopy studies, there is no obvious Fermi Level movement due to hole doping during the phase transition process, but a significant spectral weight shift occurs, which means that there is a strong electron correlation effect in the FeSe superconducting transition."
"Strong electron correlation effect... Strong electron correlation effect..."
After thinking about this, Xiao Yi took out a paper and pen and began to substitute these data into the corresponding physical formulas for calculation.
However, since these experimental data contain errors such as noise, which will affect the accuracy of the calculation results, some processing is also required.
Just like that, after some calculations, Xiao Yi suddenly narrowed his eyes.
"Huh? This error... seems a little strange?"
It is normal for errors to occur, but the problem is that there is something wrong with the errors in these calculation results.
It cannot be said that it is too big or too small, but it should be said that these errors seem to coincide with some laws.
Hmm...
This comes from his intuition. Otherwise, if you put this data in front of 99% of other people, they will probably think it is just an error.
Without drawing an immediate conclusion, he tried to bring in some other possibly relevant physical formulas for processing, but it was completely useless.
"It can't be that I discovered something new."
Xiao Yi shook his head and laughed.
But just when he thought this, he raised his eyebrows and then turned into a serious face.
Gotta Lock In.
Although intuition has some metaphysical elements in it, he still has some confidence in his own intuition.
So, maybe I am right?
"Xiao Yi, so you are here."
At this moment, a voice came from behind him.
Xiao Yi turned around to look, and then was startled. "Professor Guo? Why are you back? Is Academician Pang looking for you?"
"Ah, that's not true." Guo Ding scratched his head and smiled, "Actually, I came here specifically to ask you a favor."
Xiao Yi: "Huh? What is it? Professor Guo Please tell me."
"Hehe, it's Director Tang over at Institute of High Energy Physics. After hearing about your performance in our research group from me, I wanted me to invite you to help over at Institute of High Energy Physics. Now we happen to have a project, and we need mathematicians like you to help with analysis."
"Our Director Tang appreciates you so much."
Xiao Yi was stunned.
Another topic?
Well, this is indeed quite normal in academia. Scholars always move around between different research groups, and this is especially true for outstanding scholars.
Well... he can be considered an excellent scholar to some extent.
He asked, "What is the subject about?"
"Hmm..." Guo Ding said, "Study quark-gluon plasma and its phase transition process."
"Generally speaking, we will call this thing QGP. It basically only exists in nature for a few microseconds in the early days of the Big Bang. Therefore, studying it can also help us understand the situation in the early days of the Big Bang. Later, it will help us understand the strong interaction force. Well... it can also help us study some phase transition phenomena. Oh! By the way, we are studying superconducting phase transitions now. There may be some analogies between the two."
Can it help superconducting research?
Hearing Guo Ding talk about this, Xiao Yi looked back at his data. After hesitating for a moment, he said, "Wait a minute. Let's take a look at these experimental data first, and then these images. Do you feel anything about the errors in my calculation process?"
"What?"
Guo Ding walked forward with a confused look on his face and took a good look at these things.
After reading it, he became even more confused, "What's wrong with these data? Isn't it just an error? Isn't it normal for experimental data to have errors?"
Xiao Yi tried to explain, "Don't you think..."
Halfway through the words, he shook his head and gave up, "Forget it, okay, I agree to go with you, but I have two conditions."
"Say." Guo Ding nodded naturally.
"First, you have to help me explain to Academician Pang."
"Of course there is no problem." Guo Ding said OK, this is indeed his responsibility.
"Second, please help me find information about the experimental equipment for these data, including their specific models and specific performance parameters."
Xiao Yi said.
Guo Ding was confused again. "Why do you want these things?"
"Hmm... how should I explain it to you?" Xiao Yi thought for a while.
He wanted to compare these experimental errors through the experimental parameters of these equipment, and try to discover something from them.
Seeing Xiao Yi's appearance, Guo Ding quickly stretched out his hand and said, "Forget it, forget it, don't explain, I will help you find it."
"That's good."
Xiao Yi smiled, "Then let's leave now."
Guo Ding's eyes lit up. "OK!"
First, the two went to Academician Pang to explain.
Although Academician Pang did not refuse, he also pointed at Guo Ding: "You kid, you asked me to call Xiao Yi over at first, and then I spent a lot of effort and even talked to next door. Institute of Mathematics's Xi Lan had a big fight before Xiao Yi came, but now you help Institute of High Energy Physics call Xiao Yi over. That guy named Tang is not kind..."
In the end, Guo Ding agreed to a lot of requests. For example, if Pang Cheng needs help in the future, Guo Ding must be on call, etc.
Finally, Guo Ding brings Xiao Yi to Institute of High Energy Physics.
When Academician Tang Yifang learned that Xiao Yi was coming, he personally came to the door to pick up Xiao Yi.
"Haha, I finally got to see you in person. Your name is astonishing to my ears."
Tang Yifang smiled and shook hands with Xiao Yi. Then he nodded towards Guo Ding and said with a smile, "Xiao Guo, you did a good job this time. I will give you a credit."
Guo Ding had a wry smile on his face, thinking of the conditions he agreed to Academician Pang, he probably wouldn't be able to even get salted fish anymore.
Without staying at the door for too long, they entered the institute.
"Professor Guo should have told you everything we studied this time, right?"
Going directly to the topic, Tang Yifang asked.
Xiao Yi nodded. "Yes, I understand."
"That's okay!" Tang Yifang nodded, "Then Professor Guo, you will be responsible for explaining it to Xiao Yi from now on."
"I got it." Guo Ding said OK. Anyway, he was on this same mission with Institute of Physics.
"Yeah." Tang Yifang nodded, then looked at Xiao Yi again, and said, "Of course, Xiao Yi, in addition to computer simulation, mathematics can be used in our high-energy physics, or Theoretical Physics There are many more functions, at least much more than the research materials. Think about it, wasn't Einstein the only one who derived the theory of relativity back then? He even had to ask Hilbert for help because he wasn't very good at mathematics."
"Another example is the later Yang-Mills equation, which was basically derived mathematically, as well as Higgs mechanism and so on..."
"Of course, there is another point that is very important in physics research, and that is physical intuition."
"Physical intuition is a deep understanding of physical phenomena and theories, which goes beyond pure mathematical descriptions and formula calculations. Just through formulas or data in mathematical form, physicists may discover something that the physics community does not know."
"I'm not telling you this for any reason. I just hope that when you study our experimental data or analyze them, you can 'see' these things more deeply."
Tang Yifang smiled and patted Xiao Yi on the shoulder, "After all, your intuition is already so powerful in mathematical research, why not give it full play in physics?"
Xiao Yi thought about the intuition he had just discovered from the superconducting data, and finally nodded. "I will try my best."
Tang Yifang laughed, then said no more and left here.
Then Guo Ding took Xiao Yi into the interior of Institute of High Energy Physics.
After some introduction, Xiao Yi probably has some understanding of Institute of High Energy Physics.
In particular, the Shangjing electron-positron collider BEPC located within this institute is one of the eight largest particle accelerators in the world, which also establishes Institute of High Energy Physics as a world-class high-energy Physics Research Institute.
"Our experimental data this time mainly comes from the recent BEPC collision, which produced a large amount of data."
Finally entering a computer room, Guo Ding explained to Xiao Yi.
"The physics community has achieved electroweak unification, but the understanding of the strong interaction is very weak. Therefore, the study of the strong force is also the focus of many research institutes. As for gravity... this thing is not within the scope of discussion."
"The QGP we are currently studying is actually relatively successful. The only problem is that these are high-energy situations, in other words, extreme situations, but the research on low-energy situations is relatively weak."
"Especially the issues related to entanglement and mass gap. You must also know the mass gap problem. It is one of the millennium mathematics problems."
Click on a computer, and as the screen lights up, a bunch of data and images appear on it.
"Well, these are the experimental data. They are all on the computer. If you want to see them, you can see them at any time."
"Well... these should be the data of p-Pb collisions. QGP generally needs to be generated by the collision of protons and heavy ions. You can take a look, but in addition to these, there are also pp collisions..."
Looking at these data, Xiao Yi's mind has automatically begun to think and analyze them.
For example, how are these data generated, and why are they generated?
Comparing these data with Standard Model one by one, most of them can be matched, but there are still some small parts...
Xiao Yi squinted his eyes, looked at some points above that were extremely deviated from the distribution, and asked, "Why are these points so different from other points?"
"These." Guo Ding said very normally, "Experimental errors, there will always be some data that are erratic, which may be noise. For example, the Coulomb interaction between the beams and the residual gas in the equipment will bring all kinds of sudden noise. It is normal."
"That's right." Xiao Yi nodded, expressing understanding.
Particle collision needs to maintain a vacuum state, but obviously it is impossible to create an absolute vacuum environment on the earth. Generally, some gas molecules will exist.
If it is residual gas molecules, it may indeed cause some very prominent noise when a collision occurs.
Without thinking any more, he continued to look down, and at the same time took out a scratch paper and pen to calculate and analyze the data on these graphs.
Just like he studied the data of FeSe single-layer superconductivity in the morning.
However, as time passed, he once again felt a strange feeling in his heart.
Why... some of the errors here always made him feel that there were similar situations to the data errors in the morning?
"There's a problem."
he said.
"Huh? What's the problem?" Guo Ding next to him was currently doing a fluid mechanics simulation. Hearing Xiao Yi's words, he asked in confusion.
"Look at the data I calculated." Xiao Yi said, "Calculate them together and consider the errors, and the final result will be very strange. Look at it."
Guo Ding looked at it for a long time, but still didn't see anything. Suddenly he had a sense of instant vision, and finally quickly thought that this thing seemed to have happened in the morning.
He immediately couldn't laugh or cry, and said, "You also felt something was wrong this morning, and now you feel something is wrong. It is correct that something is wrong in physics. After all, it is not as rigorous as mathematics."
"Is that so?" Xiao Yi murmured.
He thought for a moment, then pointed to a set of images on the computer and said, "Look at this set of images, these data should be some W boson and Z boson generated during the process, right?"
"And then there's this group... this group..."
"The occurrence rate of both W and Z boson seems to be much higher than expected."
"In addition, the most important thing is that in the calculation, according to the W boson mass predicted by Standard Model, it is completely inconsistent with the result. Unless we improve the quality of W boson a little, um, about 0.1%, we can make it consistent, don't you think?"
Guo Ding:???
What do I think?
I just feel like my head is going to explode now.
Could it be that he is really a genius?
Ahem, math genius is the default, but the question is, is Xiao Yi still a physics genius?
He could actually see these problems from these data?
After swallowing, Guo Ding finally said, "I... let me call Academician Tang over for you."
You just tortured me.
I really just want to be a salted fish!