Research starts with PhD students

Chapter 25 No wonder young people have creative thinking
Experimental base, conference hall on the first floor of the central building.

Academicians Tan Zhiming and Gao Hongli sat in the main seats, with Liu Ye, Liao Zhenyu and several other researchers from the Physics Center sitting on their left.

On Tan Zhiming's right is Yu Fei, deputy chief researcher at the Experimental Physics Center of the Institute of High Energy Physics.

Bao Hexing sat next to Yu Fei.

Zhang Shuo and Luo Yongjun were arranged to sit next to Bao Hexing, which was quite close to the front compared to other people.

There were more than thirty people attending the meeting.

In addition to Zhang Shuo and Luo Yongjun, there are six invited scholars participating in the experiment, including Professor Tian Guilin from Tongzhi University, and the others are all researchers from the Institute of High Energy Physics.

Academician Tan Zhiming announced the start of the meeting.

The large projection screen at the rear shows the analysis and comparison images, and a small area with few dots on the upper left side is specially circled in red.

Liu Ye stood up and introduced, “We worked with Professor Zhang Shuo and Luo Yongjun from Soochow University to develop an algorithm for comparative deviation analysis of experiments and simulations.”

"Using this algorithm, we compared and analyzed the data of this experiment with the simulation, and the results of the analysis are displayed on the screen. The image formed by the densely packed dots above is the experimental picture displayed after the algorithm correction, and the background is the simulation picture."

"In this image, we can clearly see the difference between the experiment and the simulation. At the same time, we found an area with very few points, which is the location of the red circle on the upper left."

Liu Ye sat down after he finished speaking.

The others looked at the images on the big screen and started discussing.

Tan Zhiming waved his hand to signal everyone to be quiet, and said, "I have discussed this with Academician Gao, and we have initially determined that there are three reasons."

“One is a problem with the algorithm itself.”

He glanced to the right and called out, "Professor Bao, you are responsible for the acceptance of the algorithm project. Tell me about the situation."

Bao Hexing nodded to the others and then said, "I personally think it's not the algorithm. My team and I have studied the algorithm framework and tested the functions of each module. We didn't find any problems that would interfere with the results."

"This program is already very complete. Each module has a detailed algorithm package with very simple functions, and when combined together, there will be no problem of interfering with the results."

"If it is an algorithmic problem, I think it can only arise from the evaluation logic of the underlying basic principles..."

He was referring to the decision logic of the deviation assessment system.

Liao Zhenyu raised his hand and said, "There is no problem with the evaluation system." He added, "The algorithm report was publicly published at the experimental meeting. I believe many people have studied it."

Several other people nodded as well.

Among them was Tian Guilin from Tongzhi University, who said, "I have also studied it and found that the logic of the evaluation system is self-consistent."

“Even if there are any problems, they should have nothing to do with the results shown.”

With Bao Hexing's affirmation and Liao Zhenyu and Tian Guilin's guarantee, the issue of the algorithm problem was directly addressed.

Tan Zhiming continued, "The second possibility is the control of energy parameters, or in other words, a problem with the equipment itself."

“Everyone can speak on this aspect.”

The second possibility has a much wider coverage.

The problem of precise control of the equipment itself includes many aspects. There are several possible reasons that may affect the situation where there are few particle points in a certain area.

Several researchers stood up and spoke, proposing various possibilities.

The most likely reason is that there are large particles in the vacuum pipe at the collision site, or to put it bluntly, there are some gas molecules.

When there are air particles nearby at the moment of particle collision, the dispersion of the explosion may be disturbed, resulting in a situation where there are few particle points in a certain area.

After completing the discussion, Tan Zhiming talked about the third possibility - interference.

Particle collision experiments will be subject to various interferences, and external interference is also the biggest reason that affects the experiments.

More than a decade ago, the European Organization for Nuclear Research conducted a large-scale proton beam collision experiment. After analyzing the experimental data, they claimed to have found the signal of a new particle, and the confidence threshold for the new discovery was as high as 3σ (standard deviation).

In the field of particle physics, the threshold for a new discovery is generally 5σ.

The higher the number, the more solid the evidence for the discovery; 5 standard deviations means that the confidence level of a new discovery is as high as 99.99994%.

3σ, 99.73%, is also very high. At that time, the physicists involved in the experimental research were convinced that a new particle had been discovered.

It was later discovered that during the experiment, the vacuum pipe of the particle accelerator had just been slightly bumped, and the sound waves generated by the bump had interfered with the experimental results.

This example is enough to illustrate how great the impact of external interference is.

If we were to discuss the impact of various external interferences, we would never be able to finish it in one meeting. After several researchers spoke, Tan Zhiming stopped the discussion.

He checked the time and prepared to declare the meeting over.

Zhang Shuo suddenly raised his hand and asked, "Academician Tan, why don't you discuss the possibility that it is an unknown physical phenomenon?"

Everyone looked over.

Tan Zhiming also looked over and praised him, "You are Zhang Shuo, right? Your algorithm research is excellent."

"That's a good question. We certainly can't rule out the possibility of discovering unknown physical phenomena, but what physical phenomena are they?"

He thought Zhang Shuo definitely didn't have the answer.

Zhang Shuo and Tan Zhiming looked at each other, pursed their lips, and said, "For example, the force field is chaotic. Is there a possibility that the electromagnetic energy and the basic force cause the regional force field chaos?"

Tan Zhiming was stunned for a moment, then he couldn't help laughing, "Your idea..."

He paused for a long time before continuing, "Very innovative! No wonder they say young people have creative thinking..."

He shook his head as he spoke, then stood up and packed his things.

At the same time, it also means the meeting is over.

……

After confirming that there were no problems with the program algorithm, the project acceptance review was passed, and the subsequent work of the experimental base had nothing to do with Zhang Shuo.

Liu Ye sent Zhang Shuo and Luo Yongjun to the main entrance of the experimental base.

He kept saying, "Your research is very meaningful. It gives us an additional experimental analysis method. By comparing the experiment with the simulation, we can more clearly control the experimental situation."

"We will revise your research report and the paper will be published in JHEP. You will be the first author. As for Professor Luo..."

Liu Ye said this and glanced at Luo Yongjun.

Normally, the supervisor will be the corresponding author of the doctoral thesis, but Liu Ye could see that the research was all done by Zhang Shuo.

Luo Yongjun immediately said, "It's okay if I don't put my name on it. I've done the project anyway."

Zhang Shuo said, "I'll be the second author." He added, "Professor Luo also gave me a lot of help during my research."

In general papers, the first author and corresponding author are the most important. The second author is also an important participant in the research. The third and fourth authors are really just figureheads.

Liu Ye did not delve into it. He continued, "Academician Gao speaks highly of you. Professor Bao from the Computing Center..."

He said with a smile, "He really wants you to go to the computing center!"

Zhang Shuo said, "Thank Professor Bao for me. I have only been studying for a year and I am still a long way from graduation. I have not considered the issue of work for the time being."

"I'll tell him." Liu Ye agreed.

Zhang Shuo pursed his lips and thought for a moment. "Professor Liu, have you ever thought about developing a method to compare and analyze all the particle collision experimental data with the standard simulation images?"

Liu Ye frowned in thought and asked doubtfully, "What's the point?"

"If this is some unknown physical discovery, it cannot be confirmed by comparing only one experimental simulation data, or even by analyzing multiple experimental data."

"If we want to determine it, that is, to make the confidence threshold reach five standard deviations, we must use a large number of particles to analyze the experimental data together, and use the huge amount of data to continuously increase the confidence level..."

Liu Ye thought about it carefully, frowned and said, "What you said makes sense. The premise is to make more people believe that it is an unknown physical discovery."

“It’s not easy to do this!”

(End of this chapter)