The top student must be diligent.

Chapter 163 New Physics?
Finally, Academician Tang was called over by Guo Ding.

After arriving at the computer room, he asked with a smile: "Did Xiao Yi encounter any problems?"

"Uh..." Guo Ding nodded: "That's true."

What Xiao Yi asked is indeed a question, right?

It's just... a little beyond the scope.
When he saw Tang Yifang, Xiao Yi once again took out the results he had just calculated and explained them.

After hearing this, Tang Yifang was stunned just like Guo Ding was just now.

After hesitating for a long moment, he said, "That is to say, you think that the mass of the W boson predicted by the standard model has a large error?"

Xiao Yi nodded: "That's probably it."

"According to my calculations... it's at least 5 standard deviations."

"Five standard deviations?" Tang Yifang was startled again, then he stretched out his hand and said, "Let me see your calculation process."

Xiao Yi nodded, and then handed the draft paper he had just used for calculations to Tang Yifang.

Tang Yifang began to read.

In high-energy physics, there is a criterion called the 5σ criterion, which is widely considered to be the standard for judging whether the results are statistically significant. Among them, "σ" refers to the standard deviation in the normal distribution curve, which indicates the degree to which the data deviates from the mean.

For experiments whose results reach 5σ, it means that the results of this experiment are very likely not caused by statistical fluctuations or systematic errors, and are very likely caused by a new physical phenomenon that has not been discovered in the system.

What this means is... Xiao Yi may have discovered something that can subvert the world of physics!

Maybe even... new physics!
But how is this possible? !
Tang Yifang had the same idea as Guo Ding.

Are you kidding me?
With an attitude of disbelief, Tang Yifang began to carefully read Xiao Yi's calculation process from beginning to end.

Soon, he narrowed his eyes and found where the problem lay.

"Wait...what is this method you use to deal with errors?"

"No... The error processing method you use is completely different from the processing of W boson data by other research institutes."

"In addition, you also need to explain the statistical methods you used and how you ultimately obtained these results."

He turned to look at Xiao Yi and asked, "If you can't explain the principles of these methods, you won't be able to convince the vast majority of people."

He thought he had found the key to the problem and felt relieved.

That is to say, how could there be a problem with the mass of the W boson?

What's more, even if there really was a problem, how could Xiao Yi discover it with just a few casual calculations?

However, upon hearing Tang Yifang's question, Xiao Yi asked in confusion: "Hasn't my method been used in the high-energy physics community?"

"This method should be easy to think of, right?"

Xiao Yi's rhetorical question made Tang Yifang completely confused.

What?
This method is easy to think of?

Xiao Yi continued to explain at this time: "First of all, the most critical method is maximum likelihood estimation. I introduced an improved algorithm in it, which can process high-dimensional data more effectively and ensure the accuracy of the results."

As he spoke, he pointed at the draft paper and explained to Tang Yifang how he came up with these new methods.

"Then there is the Bayesian estimation method. You see, I introduced another simpler prior distribution model, which makes the calculation of the posterior distribution more efficient and accurate. At the same time, I also used the Markov chain Monte Carlo method. I used this method in the absolute electronic calculation principle, and now I have also added it to the processing of these experimental data."

"Of course, these are just some minor improvements in statistical methods. In addition to the error handling method you just mentioned, I mainly established an analytical framework here. This may be the key reason why you are not clear about this method."

"You see, here we first introduce an error matrix, representing all possible error sources as elements in the matrix. For these errors, we also need to divide them into controllable errors and uncontrollable errors. Controllable errors are those that can be reduced through further calibration and experimental design, while uncontrollable errors are caused by natural randomness or external environmental factors."

"Then we perform matrix decomposition. I mainly use two methods. The first is singular value decomposition, which decomposes the complex error source into a set of independent components. This allows us to identify the main error contributors and quantify the impact of each factor."

“In addition, there is a principal component analysis that helps us find the most significant error patterns in high-dimensional data.”

"And then there's..."

In this way, Xiao Yi explained his data processing method to Tang Yifang from beginning to end.

Tang Yifang thought that his mathematics skills were pretty good. Although they were still a little worse than those of pure mathematicians, he was still considered very good among physicists.

However, now faced with Xiao Yi's method which was very information-intensive, he still became confused.

"...Of course, these results are limited to my paper calculations today. My energy is limited. If I can extract more relevant experimental data and process them in a unified way, I think I can improve the accuracy a lot."

After saying that, Xiao Yi felt a little thirsty and looked around to see if there was a place to drink water. However, at this time, Guo Ding appeared out of nowhere and handed him a glass of water: "Boss, drink some water."

"Uh……"

Xiao Yi looked at him speechlessly, but didn't say anything else. He took the water and took a big gulp, which slightly relieved the dryness in his throat.
Next to him, Tang Yifang was still staring at the draft paper, reviewing Xiao Yi's explanations in his mind.

Until the end, he turned his head carefully and said to Xiao Yi: "Can you say it again?"

Xiao Yi: "...Okay."

So he repeated the methods he had used. Of course, he spoke slower this time, after all, he still had to take care of the elderly.

And this time, Tang Yifang finally understood the principle behind this method.

Although there was still a part that he didn't understand, there were some processes that even he found quite interesting.

"So, how did you come up with this method?" Tang Yifang couldn't help but ask, "Have you thought of this method before?"

"Well..." Xiao Yi said, "When I was processing the data today, I thought about it and felt that using some common methods to process this kind of data might be a little inaccurate. Then I thought about it and felt that using this method to process the data in the particle accelerator would be better."

After saying that, he noticed that Tang Yifang and Guo Ding in front of him both had expressions as if they had eaten something.

After hesitating for a moment, he quickly tried to make up for it: "Uh... maybe it has something to do with what happened before? The absolute electronic calculations I did before were also due to my participation in a two-dimensional materials research group, and there were experimental errors in it..."

Tang Yifang took a deep breath and finally said, "Okay, don't say anything more."

"Well, I will arrange a report for you. You will introduce your method in detail. After that, I will organize researchers to recalculate the mass of the W boson based on the method you proposed."

"Finally." Tang Yifang suddenly became serious again: "If you can really produce a heavyweight result, I would like to thank you on behalf of the Institute of High Energy Physics."

Hearing Tang Yifang's serious statement, Xiao Yi was stunned at first, and then he responded solemnly: "Okay!" Tang Yifang nodded to him and was about to leave. However, when he reached the door, he remembered something and turned back and said: "By the way, I will arrange your report in 10 days. In addition, a research team from CERN will come to us next week to exchange and learn. The leader of the team is George Parisi. If your method can convince him, maybe we can get more experimental data from LHC for you. Those data should be more accurate than our BEPC data."

CERN research team?
Xiao Yi was stunned again.

CERN is the European Organization for Nuclear Research, and the world's largest particle accelerator, also the largest technological creation on the planet, the Large Hadron Collider (LHC), was built with funds raised by this organization.

It is no exaggeration to call it a spectacle.

Take the comparison between LHC and BEPC. The circumference of the former is about 27 kilometers, while the circumference of the latter is only 240 meters. This shows how "large" this Large Hadron Collider is.

I just didn’t expect to meet the CERN research team.

This is actually a normal thing. Academic exchanges are common in themselves, not to mention in the field of high-energy physics. Research teams from different high-energy institutes often visit each other.

Of course, due to the status of the LHC, more often than not, teams from other places visit CERN.

Xiao Yi nodded and said, "I understand."

Tang Yifang smiled and nodded, then left.

Of course, Guo Ding is still here.

At this time, he said in surprise: "Professor George Parrish is here, this is really rare."

Xiao Yi asked doubtfully: "Do you know this professor?"

"Of course, he is also a great expert in theoretical physics," said Guo Ding. "He is very proficient in quantum field theory, statistical mechanics, and other subjects. The same is true for high-energy physics. He developed a probabilistic field theory framework for the dynamics of quarks and gluons, which can be regarded as providing guidance for our research."

"In short, he is a genius who knows everything." After a pause, Guo Ding glanced at Xiao Yi and said, "Just like you."

Xiao Yi waved his hands and said modestly: "No, no."

Guo Ding rolled his eyes.

Still being modest.

Thinking about what Xiao Yi just said, if it were true, it would really cast a dark cloud over the building of physics.

But...nowadays theoretical physics likes this kind of dark cloud the most.

Finally, he said, "No matter what, I wish you success. If you need any help in the next few days, just come to me."

"Okay!" Xiao Yi nodded.

The room fell silent, and everyone returned to thinking.

Xiao Yi looked at his draft paper again.

"Hmm... there should be some areas that can be optimized, and there are also things worth optimizing in the algorithm."

These were trivial matters to Xiao Yi. He still had 10 days left, which was enough time for him to polish this method.

However, another question arose in his mind at this moment.

"The question is... these collision data come from heavy ion collision experiments, the purpose of which is to study the QGP under the strong interaction force, but they can show that the mass of the W boson is overweight. Is there a connection?"

His gaze turned to the experimental data, and his thoughtful eyes seemed to become deeper and deeper, as if he could see the microscopic world through those winding lines, scattered points, tortuous coordinate systems, and the densely packed data.

Suddenly, something that was mentioned when he was chatting with Guo Ding before appeared in his mind.

The mass gap problem of the Yang-Mills equations.

The mass gap problem is something that has not yet been explained in the strong interaction.

The W boson is involved in the weak interaction, and now the mass of the W boson is super heavy...

Is there a connection between the two?
Of course, in a sense, the two are absolutely related. After all, if these two fundamental forces can be unified, we must be able to find a way to connect them.

Even though we have not yet achieved the unity of the two, from the perspective of dialectical materialism, there is a universal connection between all things.

Applying this to the two, one can naturally conclude that there is a correlation between the two.

However, it is not in line with the scientific view to simply draw a conclusion based on a philosophical statement.

Therefore, we still have to prove this point using scientific methods.

“Do we need to solve the problem of mass gap?”

He couldn't help but think so in his heart.

This is one of the seven major problems of the millennium.

Are you really going to rush into this issue?

Finally, he shook his head and said, "Forget it. Let's first determine whether the W boson mass is really overweight."

At present, he has drawn this conclusion based on data from no more than 100 signal events, which is totally insufficient for high-energy physics.

If it is just some ordinary discovery, perhaps a few thousand data points will be enough, but if it is an important discovery, millions of signal events may be needed to ensure high statistical significance.

In order to discover the Higgs boson, the LHC collected 5fb^(-1) of data.

fb^(-1)是一个单位，翻译过来叫做逆飞靶，5fb^(-1)就表示在一个实验中，每平方飞米的有效面积上发生了5x10^15次碰撞事件。

This is enough to show how huge the amount of data is.

Therefore, for the W boson superheavy event, such a large amount of data may not be needed, but the required amount will not be less anyway.

Only in this way can the final result convince people.

“So, there is still some work to do.”

However, Xiao Yi was already looking forward to these busy tasks.

For him, the question of whether the W boson is overweight has aroused his deep interest.

(End of this chapter)