Chapter 271 I have a small problem In the conference room, everyone's eyes were turned to Xu Qingzhou in front of the whiteboard, with interesting expressions, including surprise, astonishment, and disbelief. Xu Qingzhou was very calm. He wrote two more rows of formulas and said slowly: "In the big model, can we make the model include the contribution of both the signal and the background, allow for interference terms between them, and calculate the correction factor of the interference effect on the signal strength at the same time?" Academician Yang thought for a moment and nodded, "It's feasible, Xiao Xu, you continue." Does he really have an idea? Wang Qiming's mouth twitched. This development of things was a bit strange. He knew that Xu Qingzhou was a genius in number theory and had also done research in the quantum field, but particle physics was completely different from Xu Qingzhou's research direction. His eyes darkened, and he simply picked up a pen to verify its authenticity. Xu Qingzhou turned around and started writing on the whiteboard, muttering to himself: "If this is the case, the background model needs to be greatly modified. After all, there are interference terms, so it needs to be strengthened in order to capture the different components in the background." blah blah~ 【.hi^2(heta)=\sum_{i=1}^{N}\left[\frac{D(x_i)- F(x_i;h】 Several rows of formulas appeared on the whiteboard again. Academician Yang stared at the formula on the whiteboard with a serious expression, and began to sketch it on the notebook in front of him. The others were also busy and began to use Xu Qingzhou's method to make calculations. Zhang Changqing realized that he had thought too much. Well, this junior fellow was so powerful that he didn't need him to take the lead at all. While sighing, he had already taken out the manuscript and calculated according to the ideas Xu Qingzhou had just said.
10 minutes passed. Xu Qingzhou stopped, took a step back, looked at what he had written, turned around, smiled and said, "That's all I have in mind." In this supplement, the superposition principle and the probability amplitude addition rule are added with interference terms. Xu Qingzhou looked at Wang Qiming, "Professor Wang, do you have anything to add to the above?" "." Everyone looked at Wang Qiming. Zhang Changqing smiled in his heart and was very impressed by his junior fellow student who could actually confront a professor head-on. Wang Qiming looked a little unnatural, and forced a smile: "No, the idea you provided is not bad." In fact, Xu Qingzhou's method is very good. It can at least increase the efficiency of eliminating background by 50%, but it is a bit frustrating. The word "not bad" is his last stubbornness. At the front, Academician Yang shook his head helplessly, thinking that this little guy was quite vindictive. Shen Yuanjie had a smile on his face. Although they were both from the Academy of Sciences, he also felt that Wang Qiming was going too far. A man in his forties or fifties was making things difficult for a teenager. On this side, Xu Qingzhou smiled and returned to his seat. In the corner, Chen Peipei secretly glanced at Xu Qingzhou who had just sat down. Well, now it seems that this little brother is completely different from herself. Academician Yang coughed lightly, nodded slightly, and said approvingly: "The method Xiao Xu just provided is very feasible, Team Leader Shen." Shen Yuanjie took over the conversation and promised: "Don't worry, we will definitely complete it as soon as possible." Most of the improvement plans proposed by Xu Qingzhou involve the model, which is what he is responsible for. Academician Yang nodded and said in a deep voice: "The Americans are much faster than us. I heard that they are already doing the final demonstration today." As soon as Academician Yang's words came out, everyone suddenly felt pressured. Wang Qiming's face was not very good. He wanted to teach Xu Qingzhou a lesson, but... Call ~ He sighed secretly in his heart and comforted himself: As long as the plan can be perfected, it is better than anything else.
"That's it. There are still two days until the report meeting. I hope that in these two days, we can implement everything we just discussed." "Let's go, let's get to work." End of the meeting. Zhang Changqing put his arm around Xu Qingzhou's shoulders and said admiringly, "Junior brother, you're awesome!" Shen Yuanjie was laughing beside him. Xiao Zhang's words were rude but reasonable. He asked again, "How did you come up with this improvement method?" Xu Qingzhou said: "Particle physics and my research direction are different, but the objective laws they follow are the same." Shen Yuanjie and Zhang Changqing nodded, agreeing with each other, but also feeling a little emotional. The objective laws of the world are there, but the problem is that not every researcher can notice them. With a new plan, everyone started to get busy again. August 8. At 17 o'clock in the morning, after lunch, Xu Qingzhou followed Academician Yang to the lecture hall. At 8 o'clock, the program meeting officially began. The lecture hall came into view. Academician Yang turned to look at Zhang Changqing and asked with a smile, "Xiao Zhang, is everything ok?" Zhang Changqing is the spokesperson for the Xia State Group at this meeting and needs to go on stage to explain the plan. "I'm ready." Zhang Changqing was very confident. After two days of calculations, a multivariate method for identifying photons was added to the scheme, which also provided correction factors for signal intensity and calibration of photon energy due to the interference effect between the signal and the background. This plan is perfect and if nothing unexpected happens, we will win. Today is the most relaxing day for Xu Qingzhou in recent times. He usually gets up at around seven o'clock to do calculations. At the entrance of the conference building, Academician Yang stopped with Xu Qingzhou and Zhang Changqing to greet the acquaintances on the opposite side. The leader was a white-haired old man, followed by a blonde woman. "Professor Yang, we meet again." Abby Baker said enthusiastically. Academician Yang smiled and extended his hand: "Long time no see." "Let's go. I believe we will be able to hear two wonderful project reports today." Professor Baker made a gesture of invitation. Academician Yang also said: “I am looking forward to it too.” The five people walked towards the meeting room. Entering the building, Professor Baker said with a smile, "We were having a barbecue party last night. We wanted to invite our friends from Xia Country, but I heard that you were rushing to finish the project. That's a pity. After the experiment is over, we must have a good drink together." "There is an old saying in the Xia Kingdom, 'Slow work produces fine work.'" Professor Baker nodded and praised: "You Xia people are very careful. I agree with what you often say. The Pacific Ocean can accommodate both the United States and Xia. If we have your assistance in the next experiment, we will definitely have good results." Academician Yang smiled faintly, with a good attitude, or he was confident that the revised plan was very good, better than any previous plans. The atmosphere was already tense before the meeting even started. When Xu Qingzhou entered the venue, there were already more than 20 people in the lecture hall, including the LHC expert group and other members participating in the experiment. After Zhang Changqing finished communicating with the staff, he came over to chat with Xu Qingzhou.
"This old man is Abby Baker, the head of the American team. How should I put it? He's very capable, a top expert in particle physics, but he's a bit mean." As he spoke, he looked at the woman on the podium. "That woman is his student, Mia Lane. She has learned a lot from Abby Baker and is a very powerful person." Xu Qingzhou couldn't help but take a second look at the woman who was talking to the staff on the podium. She was less than 30 years old, had a few freckles, and a blank expression on her face - comparable to the aloof school beauty Song. The reason I was interested was that I had heard of this woman's name before. At that time, she was already a world-class particle physicist. Mia seemed to notice someone was observing her and looked over. Yes, it’s the guy named “Xu Qingzhou” from Xia Country. Mia's eyes were cold, but for someone like Xu Qingzhou who had been threatened by Song Yao's death gaze countless times, there was no pressure at all. The two people's eyes met briefly in the air, and then they each went about their own business. There were still 10 minutes left before the meeting started. Xu Qingzhou took out his phone and chatted with Song Yao. Xu Qingzhou: "Are you busy?" Song Yao: "Not busy, just read a book at home." Song Yao: "Photo\jpg." In a corner of the desk, Er Miao was lying lazily, continuing his sunbath in Yandong Garden. Xu Qingzhou: "No, I want to see yours, so that I can make up for the pain of missing you." After 2 minutes. Song Yao: “Photo\jpg” Wow, it's interesting that she is still wearing her high school uniform at home. Xu Qingzhou smacked his lips and clicked save, while at the same time thinking about asking Song Yao to take the clothes back. Xu Qingzhou: "It took you so long to post the photos. Did you go in front of the mirror to tidy up?" Song Yao said nothing and pretended to be dead. Xu Qingzhou: "You are already an old married couple, why do you still need to be idols? I have seen you in all your slovenly looks." Song Yao: "Fist\jpg." If he were around, he would probably be beaten by Song Yao. After chatting with Song Yao for 10 minutes, seeing Mia already adjusting the microphone on the stage, Xu Qingzhou put down his phone and opened his notebook. "Good morning, ladies and gentlemen." After saying hello, Mia got straight to the point: "First, I will explain the overall structure to you. We all know that the background problem is the main obstacle to two-photon channel analysis." Mia's voice echoed in the lecture hall, and Xu Qingzhou also had a general understanding of the American group's plan. From the framework point of view, the methods used by the other party had a lot of overlap with theirs. For example, in the initial part, because the background yield is often much higher than the signal yield, everyone needs to select the event accurately at the beginning.
Next, appropriate data-driven methods are used to assess the level of background generation. As for the background problem, Monte Carlo simulation was chosen, and a large amount of simulation data was generated using the simulation tool GEANT4. Of course, there are overlaps, and the two groups have different choices in physical and mathematical tools. For example, the signal model building methods used when establishing the model are completely different. They use the Gaussian function, while the American group uses the Brett-Wigner function. The biggest difference is that the American group used renormalization group theory to suppress background events, while the Xia Guo group used the superposition principle and probability amplitude addition rule of quantum mechanics. “Renormalization group theory.” Xu Qingzhou narrowed his eyes and did not continue listening. Instead, he picked up the pen and started calculating. The renormalization group is a mathematical tool for examining the changes in physical systems at different length scales. The physical effect, that is, subtracting the background and using the truncation technique to set the upper limit of the integral to a finite value, is used to deal with perturbation divergence problems in experimental data and to improve the accuracy of measurement results. In addition to quantum field theory and particle physics, this theory is now more used in condensed matter physics. The reason why Xu Qingzhou focuses on this is simple: at present, the renormalization group theory is actually imperfect. It seemed that it was not corrected until seven or eight years later. If this theory is used, it is very likely that the mass of the Higgs particle will change with the change of energy scale. This will lead to differences in the properties of Higgs particles obtained at different energy scales. The renormalization group equation is: 【[μμ+β( gＲ－γΓ( gR)】ΓＲ= 0】 While Xu Qingzhou was immersed in his calculations, the expressions of Academician Yang and others next door were a little solemn. Their mood was like a roller coaster. They were happy that the plan was stable last night. Who knew things would take a sudden turn for the worse today. The American team's plan is very complete, and even if they look at it with a very critical eye, they can't find any major problems at the moment. Compared with their plan, it's basically a 50-50 split. With similar completion rates, the chances of Xia Guo's team winning are not great. After all, the relationship between the United States and European countries is beyond description. 60 minutes. Mia finished her project report, looked around, and asked, "Does anyone have anything to add?" Everyone in the conference room discussed quietly, but including the CMS expert in the front, they all shook their heads slowly and said "perfect". Professor Baker smiled gently. He was not surprised by this scene. Yes, although he spoke very easily in front of the Xia people, in fact, the whole team was still busy for several days. After the plan came out, he discussed it more than a dozen times. I am absolutely sure that there is no problem with this plan. You can be proud but you cannot underestimate your enemy, especially when facing the Xia people. Mia looked around again to see if anyone had any questions. This time, she focused on the direction of the Xiaguo group. Her eyes were calm but extremely provocative, waiting for her competitors to find loopholes. Academician Yang shook his head and sighed helplessly, fearing that he would miss out on taking the lead in the initial experiment.
Zhang Changqing and others showed bitter expressions on their faces. Although they were very unwilling, they also shook their heads. Mia's gaze paused and fell on the young man who was concentrating on writing something on the side. However, the other party was very serious and didn't pay any attention to her at all. The result is no longer in suspense. Seeing everyone shaking their heads, Mia closed her notebook and prepared to make her final thanks before leaving the stage. "Wait a minute, I have a small question." At this moment, a sudden voice was heard in the conference room. In an instant, everyone's eyes turned in the direction of the voice, and what came into their eyes was a still childish face of a Xia person. Mia was also stunned for a moment and put down the notebook in her hand. "Whoo~" Xu Qingzhou let out a long breath and looked at the manuscript paper in front of him, thinking that after all the hassle, he had finally caught up. The most surprised people should be Academician Yang and others around Xu Qingzhou, all of whom looked a little surprised. They had already prepared themselves mentally. After all, with things like literature, one can turn defeat into victory through subjective judgment, but for research, 1 is 1 and 2 is 2. Moreover, although it is very unwilling, it is normal to have winners and losers. In the experiment in March, the Xiaguo group defeated the British group. They all had a common question in their minds: What's wrong with Xu Qingzhou? Xu Qingzhou has already spoken: "Regarding the renormalization group, the third part of the report, point 45, is shown on page 9. The formula \frac{d m_H^2}{d \ln \mu}=\alpha \cdot m_H^2 +\beta \cdot g^2." "By numerically solving the renormalization group equation, we can obtain the curve of MH^2(λ) varying with λ. Have you ever tried to substitute the Higgs particle Yukawa coupling constant?" (End of this chapter)