Great Country Academician

Start with the study of "the phenomenon of asymptotic freedom of quarks" and "quark confinement". This is David Gross's suggestion to Xu Chuan.

If he is not the chairman of CERN, he has some knowledge of most of the collision experiments and analysis data, and I am afraid that there is no way to give advice.

After all, this is a field that few physicists have stepped into.

It's just that he didn't know how much the young man in front of him knew about these two fields.

After all, he is too young.

According to common sense, this age is still in the stage of learning and absorbing knowledge, even if some achievements can be made in certain fields, it is only relative.

Because of his age, he is destined to lack a lot of basic knowledge in other fields.

But for now, it seems to be inspired?

Maybe it's because the teenager has been exposed to these two aspects of knowledge in the area of ​​physics study?

In any case, he had great hopes for the young man in front of him.

From where Witten learned about him, to when he stood on the podium to solve the mystery of the proton radius not long ago, Gross saw the talent and talent of this young man.

This is genius, real genius.

Whether it is in terms of mathematics or physics, he has what can be said to be a top-level talent, and he has also stepped out of his own path in both mathematics and physics.

Many people think that academics or research should be single-minded and focused, but David Gross does not think so.

In his opinion, as long as you like it, you can do it.

Do what you like; dare to ask questions and take risks. Young people should dare to try. You can fail if you try, but you can't succeed if you don't try.

Moreover, doing what you like, even if you fail, is also happy.

For the boy in front of him, Gross hopes that he can go further.

For a person like him who has devoted his whole life to physics and has already buried half of his body in the ground, there is nothing more gratifying than seeing successors in the field of physics.

In the office, Xu Chuan fell into deep thought.

He continued to think about it following the guidance of Professor David Gross.

He is very clear about the two fields of "asymptotic freedom of quarks" and "quark confinement" mentioned by Professor Gross.

Both of these are knowledge in the field of particle physics.

The former is the result of the old man in front of him winning the Nobel Prize.

It is a counter-intuitive phenomenon of amazing physics.

In a nutshell, it boils down to the idea that the nuclear force of an atomic nucleus weakens over short distances, allowing the quarks in the nucleus to behave like free particles. But when the distance between the two quarks in the nucleus increases, the attractive force that binds them becomes stronger.

This characteristic can be likened to a kind of rubber band. The longer the rubber band is stretched, the stronger the rebound force will be, but when you don't pull it, it will be loose.

This is the "asymptotic free phenomenon of quarks", which can be perturbed through the cross-sectional DGLAP equation of deep nonlinear scattering in particle physics, thus deriving the subject of "quantum chromodynamics".

In 2004, three physicists David Gross, David Politzer and Frank Wilczek won the Nobel Prize for this.

And 'quark confinement' is also a physical phenomenon.

What is described is that quark particles do not exist alone.

We all know that quarks are the basic unit of matter.

Quarks combine with each other to form a composite particle called a 'hadron'.

For example, the most stable particles among hadrons are 'protons' and 'neutrons', which are the basic units that make up the atomic nucleus.

Due to the strong interaction, quarks with color charges are confined to other quarks so that the total color charge is zero.

The force between quarks increases with distance, so no quarks can be found alone.

To put it simply, because of the strong interaction, quarks cannot exist in pieces like 'protons' or 'neutrons'.

It is always in pairs, or huddled together for warmth.

For example, a proton is composed of two up quarks and one down quark through the strong interaction of gluons.

Or the pentaquark particles discovered by CERN through LHC last year, etc.

However, is there any relationship between these two theories and the use of mathematics to narrow down the optimal search decay channel for the Yukawa coupling between the Higgs and the third-generation heavy quark?

In theory, these three can be said to be three completely different things.

Even if Xu Chuan looked at it from the perspective of the physics world twenty years later, the three of them would not have much to do with each other.

If there is a relationship, it is the "quantum chromodynamics" derived from the "asymptotic free phenomenon of quarks", which has a certain relationship in the study of the strong interaction force.

However, it seems that this aspect cannot be applied to the most ideal search decay channel for finding the coupling between Higgs and Yukawa of the third generation heavy quark.

However, it is obviously impossible for a Nobel Prize-winning scholar to be aimless. Since Professor Gross suggested to study from the direction of "asymptotic freedom of quarks" and "quark confinement", there must be something hidden in it.

These things can definitely be applied to the search for the most ideal decay channel for the Yukawa coupling of the Higgs and the third-generation heavy quark.

It's just that he hasn't seen it.

Physics is so big that even if he is a top physicist reborn after twenty years, it is impossible to be familiar with every knowledge point.

Of course, it is more likely that this is just an idea that was born in the mind of Professor David Gross these two days.

This is like the evolution of organisms. Without external stimuli, it is impossible for organisms to mutate and evolve.

Normal physicists don't study this stuff at all.

If it weren't for the email he sent to the professor yesterday, the old man probably wouldn't have been thinking about this kind of question in his mind.

It is only normal that ideas born out of accidents will not be passed down in the future.

Xu Chuan is not entangled in this aspect, he is thinking about how to study the optimal search decay channel from the direction of "asymptotic freedom of quarks" and "quark confinement".

The old man across the desk obviously had some ideas in this regard, but he didn't say it directly, but gave a hint.

This should be a test for the old man, to see his physical talent or ability.

Even if he can't come up with any results in the end, the other party should tell him the complete idea.

But it is impossible for Xu Chuan to give up his independent thinking like this. If he can't do it when he already has a clue, he is not worthy to stand at the pinnacle of the physics world.

All kinds of knowledge in the mind were flipped quickly, starting from the "asymptotic free phenomenon of quarks", to quantum chromodynamics, from "quark confinement", to the vacuum excitation of the lowest energy state.

A series of knowledge points quickly formed a tortuous but connecting thread in Xu Chuan's mind.

Suddenly, he seemed to think of something, raised his head suddenly, and stared at the old man across the desk with sparkling eyes.

"Soft gluon resummation effects in transverse momentum distribution?"

Hearing this, Professor David Gross looked surprised, and asked in surprise, "How did you come up with this idea?"

He didn't expect the young man in front of him to find a breakthrough in such a short period of time.

After receiving the email yesterday afternoon, he thought about it all night. Using the countless collision experiments and analysis data he had been exposed to at CERN over the years, he found a plausible path, which took no less than five or six hours.

Unexpectedly, Xu Chuan found this hidden intersection point after thinking for less than five minutes.

Even though there was his prompt first, this is too incredible.

The soft gluon resummation effect of transverse momentum distribution can be said to be the most advanced and unpopular field in today's physics circle.

This field is used to calculate the color interference effect between the initial state and the final state of particles.

But in today's physics world, the collider is still looking for new particles and checking whether the standard model is correct, so how can anyone pay attention to the color state interference effect?

Those who know something about this area can be counted in the entire physics world.

He wouldn't have known this knowledge if he hadn't been chairing CERN's board of directors.

He was quite surprised that Xu Chuan could find a breakthrough so quickly.

Xu Chuan smiled, and replied: "I have learned some calculation methods on the leading level of QCD."

Hearing this, Professor David Gross suddenly understood.

The calculation at the leading level of QCD is based on the results based on the QCD soft-collinear effective theory.

However, part of the soft-collinear effective theory of QCD involves the knowledge of the resummation effect of soft gluons in the transverse momentum distribution.

If this is the case, we can indeed find a breakthrough along this clue.

But I have to say that, following the clue of "asymptotic freedom of quarks" to find the breakthrough of the soft gluon resummation effect in the transverse momentum distribution, the thinking of the young man in front of him is really jumpy enough.

In other words, his intuition and talent in physics and mathematics are really amazing.

After all, there are many tortuous knowledge points in the middle. Even if you have learned QCD calculations at the leading level, it is not so easy to deduce it smoothly.

It's like playing a game.

Ordinary players only consider the lineup and opponents in front of them, while high-end players will consider the next move.

And some people, with unparalleled talent in the game, can count to farther places, and even declare the end of the line when the pawn line is hit by the opponent.

It sounds outrageous, but there are people with such talents.

This is true in the gaming world, as well as in academia.

If you give some genius a little inspiration, he can return a lot of results.

For example, Newton discovered the law of universal gravitation when he was hit by an apple. Ordinary people are hit by an apple, and they will just stuff it into their mouths.

After bidding farewell to his master, Professor David Gross, Xu Chuan went straight back to the hotel room.

With inspiration and inspiration, the road ahead will be much easier.

Shrunk in the hotel room, starting from the calculation of the resummation effect of soft gluons in the transverse momentum distribution, he began to use the Daritz diagram in his hand to perform data calculations.

I don't know how long it has passed, and a cell phone rang suddenly in the silent room.

The calculation was interrupted, Xu Chuan impatiently picked up the phone from the table, and said 'Hello' after connecting.

"Junior brother, the acceptance report meeting for this experiment is about to start, where are you? I sent you a message and didn't reply."

Senior brother Qi Xishaoqi made the call. After hearing this, Xu Chuan came back to his senses. He glanced at the time in the lower right corner of the notebook screen, and before he knew it, he had been in the hotel room for three full days.

Xu Chuan asked, "Which conference room is it in? I'll go there now."

He had to go to this report meeting no matter what.

After all, he is a member of the project team. Although he joined in the middle and late stages, he is still a member. He should attend the scientific research project report meeting he participated in.

If in the report meeting, someone has any objection to the part of the analysis data that he is responsible for, he is obliged to explain.

Fortunately, this time using mathematics to find the most ideal search decay channel for the coupling between Higgs and the third-generation heavy quark Yukawa has a fixed direction, and the rest of the work can be gradually improved, and there is no need to worry about the inspiration flying away. up.

"Lecture Hall No. 2 is about to start, hurry up."

Xu Chuan responded, hung up the call, rushed into the bathroom, washed his face, and tidied his messy hair.

If time permits, it is appropriate to take a shower and tidy up your appearance before going there.

But unfortunately time does not allow now.

He rushed to the No. 2 lecture hall in a hurry, and the acceptance report meeting had already started.

As a member of the project team, Xu Chuan has his own fixed position, right next to Qi Xishao.

"Fuck, little junior brother, what have you been doing these two days? How did you become like this? Although you are young and powerful, you should also pay attention to the number of times and protect your waist."

As soon as he sat down, Qi Xishao's voice came over.

He was taken aback by Xu Chuan's state. Although his hair had been tidied, it was shiny, as if it hadn't been washed for several days, and his eye circles were dark, as if he had been up for several days and nights. It looks like it has been overdrawn a dozen times.

Reminiscent of not seeing this little junior in the office these days, he naturally thought that this little junior went to play at the Gaul chicken next door.

Xu Chuan rolled his eyes and said, "What are you thinking about? I've been in the hotel for the past two days, and I have some ideas about my previous thoughts. I'm checking the calculations for the past two days."

"Looking for the most ideal decay channel coupling between Higgs and Tang Chuan of the third generation of heavy quarks? You haven't given up yet?" Qi Xishao asked in surprise.

Xu Chuan nodded, and Qi Xishao sighed: "Pay attention to your body, scientific research is important, and your body is even more important. It's not worth it to be exhausted."

Although there is no lack of diligence and hard work in academics, it is really rare to be as diligent and hardworking as this little junior.

Qi Xishao thought that he was hardworking enough, but he also had some other hobbies.

And this little junior doesn't seem to have any other interests besides academic research?

Anyway, during the few months he was in contact with CERN, he did not see Xu Chuan showing other hobbies. The basic activities were all related to scientific research, and he was often seen lying in front of the table for a long time.

It can only be said that it is reasonable for him to solve a world-class problem in mathematics and physics at the age of eighteen.

If such a person is not successful, who will succeed?

Xu Chuan smiled shyly and said, "I will pay attention."

"Wait, you just said you found a method? Calculated the most ideal search decay channel?"

Really sighed, suddenly, Qi Xishao remembered something, turned his head suddenly and asked in surprise.

He seems to have heard this little junior say that he has an idea and is calculating?