At the Institute for Advanced Study in Princeton, Xu Chuan searched around but couldn't find his mentor, Edward Witten, and couldn't get through on the phone.

Finally, he found his senior brother Lin Feng and asked about it, only to find out that the old professor was no longer in Princeton, and had flown to the European Atomic Energy Laboratory a few days ago.

Xu Chuan couldn't help but hang up the phone. This old gentleman was really treating him.

Except for assigning him a task when they first met, he ignored him and didn't assign him a task as a teaching assistant. The two of them didn't have much communication at all.

So in the end, he, the student, had no idea where the instructor was.

...

Shaking his head, Xu Chuan was about to return to his dormitory, but then he made a mistake and walked towards Professor Deligne's office.

Since you are here, there is no reason not to say hello to this instructor.

Knocking on the door, a voice came from inside. Xu Chuan opened the door and walked in.

Compared with Witten, who is flying all over the sky, Deligne's whereabouts are quite fixed, and he is often in the office of the Institute for Advanced Study in Princeton.

Seeing that the person who came in through the door was Xu Chuan, Deligne put down the ballpoint pen in his hand and asked, "How is your research going?"

Although he didn't ask the disciple in front of him what he was going to do on leave, he could guess that, not surprisingly, he should be studying the 'mystery of the proton radius'.

As a tutor, it is normal to care about the progress of your students' research projects.

Xu Chuan: "It's done."

Hearing this, a trace of surprise flashed across Deligne's dark brown eyes.

If he remembered correctly, it had only been a week since the student in front of him asked for leave, right?

Can that problem be solved in a week?

It looks impossible no matter how you look at it.

"Show me your new method."

Deligne said, he knew that Xu Chuan must be carrying the manuscript with him.

"Hold on."

Xu Chuan responded, took off the backpack behind him, took out a stack of manuscript paper, and handed it over.

Professor Deligne took the manuscript paper and looked down.

He is not as ignorant about the mystery of the proton radius now as he was before. He had talked with Witten about this aspect some time ago.

This is a problem for the entire physics community. Since this problem appeared in 2010, the precise charge radius of the proton has never been able to obtain a relatively stable value.

It jumps repeatedly between 0.879± 0.011 fm and 0.833± 0.00067 fm.

The diameters of the same particle measured using two different methods have huge differences, which are so large that they exceed the allowable error range and are so large that they directly shake the foundation of the building of particle physics.

Five or six years have passed, and the physics community has still not found the reason for this gap.

It is also impossible to determine which of the measured values ​​is more biased toward the correct proton charge radius.

This kind of problem, if put in the mathematical world, is tantamount to a problem at the level of the twin prime number conjecture.

However, physics is a bit more special than mathematics.

All mathematics can rely on is a pen, a piece of paper, and a researcher's brain.

Physics is different. Many physical problems can be solved through physical experiments.

Just like the problem of the proton radius mystery, it appears in physical experiments, and the final solution must be completed by physical experiments.

But it may take a long time.

After all, no one knows how long it will take for the physical equipment used in experiments to be developed, updated and iterated.

You may have a breakthrough as soon as you wake up, or you may still be stuck in the same place ten years later.

Mathematics can help physics solve problems in advance when the equipment performance is insufficient.

For example, the problem of the proton radius puzzle, the radius of the proton can be calculated theoretically through the first principles of mathematics.

It's just that no one can do it yet.

The first principles calculation of proton information inside the nucleus is so difficult that it has been directly upgraded from the twin prime conjecture level to the Goldbach conjecture level.

Deligne did not think that his student could calculate the proton radius from first principles in such a short period of time. This was impossible, and his mentor Grothendieck could not do it even after he was resurrected.

But even a new method for calculating the radius of a proton would be an incredible achievement.

........

In the office, Professor Deligne flipped through the manuscript paper in his hand.

Xu Chuan was not polite. He found a cup and made a cup of coffee. He also found a mathematics journal and read it while waiting.

The quality of the coffee in Professor Deligne's office is very good, and it is all expensive hand-ground coffee.

But to be honest, he couldn't tell much difference between this kind of handmade coffee and instant coffee.

Maybe the taste is more delicate?

He wasn't interested in coffee anyway, but there was nothing else to occupy his time now.

.......

Xu Chuan drank a cup of coffee slowly, and Professor Deligne hadn't even finished reading the manuscript paper in his hand.

After waiting for a while, he sorted out the manuscript documents and handed them back again.

"Pretty precise mathematical calculations. Your mathematical ability in functional analysis is much deeper than I imagined. If you hadn't seen it with your own eyes, it would be hard to imagine that these things were produced by a young man who is not yet twenty years old."

Even when facing his own students, Deligne did not hesitate to praise him.

In fact, the mathematical methods used in this calculation method are very subtle even for him, especially the Fourier transform of the three-dimensional spatial distribution of proton charges used to finally solve the problem of atomic elastic scattering interface charge interference.

He got some inspiration from it, otherwise he wouldn't have read and thought about it for so long.

Moreover, praising this thing may make other students inflated and have negative effects such as conceitedness, but for the disciple in front of him, he has enough qualifications to inflate.

This chapter is not over, please click on the next page to continue reading! Looking at all the mathematicians under the age of 30 in the entire mathematics world, it can be said that no one can compare with him.

Hearing Deligne's exaggeration, Xu Chuan smiled shyly and said, "Compared to you, teacher, I still have a lot to learn."

Deligne: "This new calculation method is very good. Although I am not sure whether it is correct for the physics world, the mathematical method in it is quite exquisite. Who are you going to vote for it?"

Xu Chuan shook his head and said: "This is not clear yet, and I haven't thought about it yet. Maybe I should let Instructor Witten read it before making a decision?"

Deligne looked at the calendar on the table and said: "Today is July 4th. Witten may not be back until close to the 10th. You can sort out the documents first, enter them into the computer and send them to him by email.

You can also hang it on arxiv first."

The arxiv preprint server was originally a place for physicists to communicate.

Although it is now occupied by computers, it is undeniable that there are still many physicists exchanging their ideas on it.

Xu Chuan nodded and said, "I will do this."

Deligne smiled and said: "If this method is correct, the world of physics will be shaken by you."

He was not exaggerating. Since its emergence, the problem of the proton radius has aroused confusion and pursuit in the entire particle physics community, and even in the fundamental physics community.

Solving this mystery is significant for understanding the laws of physics, not just because the physics community has a more precise data.

It has greatly promoted the development of physics, such as the quantum electrodynamics theory that describes how light and matter interact.

.........

Returning to his dormitory from the Institute for Advanced Study in Princeton, Xu Chuan sorted out the calculation methods related to the 'proton radius mystery' and entered them into the computer.

This is a very boring job, but it also requires a lot of patience and care. You need to constantly check every character entered into the computer to see if there are any errors.

In this kind of paper, if you enter a wrong word, character, or even punctuation mark, it may cause serious consequences.

At worst, the reviewing editor may think you are unprofessional; at worst, it may cause the entire proof process of the paper to be scrapped.

Especially in the world of mathematics, it's not like this has never happened before.

Previously, when a mathematician in the United States completed the promotion of a certain real number theory with exponential functions, he entered a certain mathematical symbol incorrectly when uploading it.

As a result, when the journal reviewed it, it was directly rejected and said that there were serious errors in the core proof process of the paper.

But fortunately, this error was discovered during subsequent inspections, and after completing the modifications, it finally passed the review smoothly.

Xu Chuan didn't want to make this kind of mistake. It would make people laugh and it would be embarrassing if he said it.

........

It took Xu Chuan more than a day to input all the calculation methods on the manuscript paper into the calculation.

After checking and confirming that there were no problems, he first uploaded it to the arxiv preprint server, then found the email address of his mentor Witten and sent it there.

】

After thinking about it, Xu Chuan opened his email again, found his mentor at NTU, Chen Zhengping, among his contacts, and sent him the calculation method for the 'proton radius mystery'.

In name only, he is still a doctoral student at NTU.

He came to Princeton to study for a Ph.D. in the name of an exchange student, but he did not use the school's exchange student quota, but his own invitation letter, so there was no limit on the time limit for studying abroad.
To be continued...