Chapter 271 I have a little question
In the conference room, everyone looked at Xu Qingzhou in front of the whiteboard, with wonderful expressions ranging from surprise, astonishment, and disbelief.
Xu Qingzhou was very calm, wrote two more rows of formulas, and said slowly: "In the large model, can we make the model include the contributions of both the signal and the background, allow the interference terms between them, and calculate the interference effect at the same time? Correction factor for signal strength ”
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 was a bit strange. He knew that Xu Qingzhou was a genius in number theory and also conducted research in the quantum field, but particle physics and Xu Qingzhou's research directions were completely different.
His eyes darkened, and he simply picked up the pen, intending to verify the authenticity.
Xu Qingzhou turned his head and started writing on the whiteboard, saying to himself: "If this is the case, the background model needs to be greatly modified. After all, there are interference terms, which must be strengthened in order to capture different components in the background."
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Ta-ta-ta~
【.hi^2(heta)=\sum_{i=1}^{N}\left[\frac{D(x_i)-F(x_i;h】
The numerical formula appears again on the whiteboard.
Academician Yang stared at the formula on the whiteboard with a serious expression and sketched it on the notebook in front of him. Others were also idle and began to use Xu Qingzhou's method to make calculations.
Zhang Changqing found that he was overthinking it. Well, this junior brother was so powerful that there was no need for him to step forward at all. In the midst of emotion, he had already pulled out the manuscript paper and calculated based on the ideas Xu Qingzhou just mentioned.
10 minutes passed.
Xu Qingzhou stopped, took a step back, looked at what he had written, turned his head, and said with a smile: "That's all my thoughts."
In this supplement, the superposition principle and the probability amplitude addition rule also add interference terms.
Xu Qingzhou looked at Wang Qiming, "Professor Wang, do you have anything to add to the above?"
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Everyone looked at Wang Qiming.
Zhang Changqing laughed in his heart and admired this junior fellow student for actually having a direct conversation with a professor.
Wang Qiming looked a little unnatural and forced a forced smile: "No, the idea you provided is good."
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 final 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 he was from the Academy of Sciences, he also felt that Wang Qiming was going too far. A man in his forties or fifties was still embarrassing a teenager.
At this end, 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 this little brother looks completely different from himself.
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 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 making the final argument today."
As soon as Academician Yang's words came out, everyone suddenly felt pressure.
Wang Qiming didn't look very good. He originally wanted Xu Qingzhou to teach him a lesson, but in the end.
Phew~
He sighed secretly in his heart and comforted himself: As long as he can perfect the plan, it is better than anything else.
"That's it. There are still two days before the report meeting. I hope that within these two days, we can implement everything just now."
"Let's go, let's start work."
The meeting is over.
Zhang Changqing put his arm around Xu Qingzhou's shoulders and said with admiration: "Junior brother, you are awesome!"
Shen Yuanjie smiled beside him. Xiao Zhang was not rude, so he asked again: "How did you come up with this improvement method?"
Xu Qingzhou said: "Particle physics and my research directions are different, but the objective laws we follow are the same."
Shen Yuanjie and Zhang Changqing nodded, agreeing, but also feeling a little emotional. The objective laws of the world are there, the problem is, not every researcher can notice them.
With the new plan in place, everyone started getting busy again.
August 17th. At 8 o'clock in the morning, after dinner, Xu Qingzhou followed Academician Yang to the lecture hall. At 9 o'clock, the planning meeting officially started.
The lecture hall appeared in sight. Academician Yang turned to look at Zhang Changqing and asked with a smile: "Xiao Zhang, is there no problem?"
Zhang Changqing is the spokesperson of the Xia Guo Group at this meeting and needs to go on stage to explain the plan.
"It's ready." Zhang Changqing was very confident.
After two days of calculations, a multi-variable method for identifying photons was added to the plan. It also provided a correction factor for the interference effect between the signal and the background on the signal intensity and a calibration of the photon energy.
This plan is already perfect, and without any surprise, it will win.
Today is the most relaxing day for Xu Qingzhou in a while. He usually gets up at around seven o'clock to do calculations.
At the entrance of the conference building, Academician Yang, Xu Qingzhou and Zhang Changqing stopped and greeted the acquaintances opposite. The leader was an old man with white hair, followed by a blonde woman.
"Professor Yang, we meet again." Abby Baker said enthusiastically.
Academician Yang smiled and stretched out his hand: "Long time no see."
"Let's go, I believe we will hear two wonderful program reports today." Professor Baker made an inviting gesture.
Academician Yang also said: "I am also looking forward to it."
The five people walked towards the conference room.
Entering the building, Professor Baker said with a smile: "We were having a barbecue party last night. We originally wanted to invite friends from Xia Guo over, but I heard that you are rushing to meet the plan. It's a pity. We must have a drink when the experiment is over. ”
"There is an old saying in the Xia Dynasty, which is 'slow work produces careful work'."
Professor Baker nodded and praised: "You Xia people are very careful. I agree with what you often say. The Pacific Ocean can accommodate two countries, the United States and Xia. The next experiment, with your assistance, will definitely be able to There are good results.”
Academician Yang smiled lightly, with a good attitude, or in other words, he was confident. The revised plan was very good, better than the previous plans.
Even before the meeting started, there was already a smell of tit-for-tat tensions.
When Xu Qingzhou entered the venue, there were already more than 20 people in the lecture hall. In addition to the LHC expert team, there were also other members participating in the experiment.
After Zhang Changqing communicated with the staff, he came over to chat with Xu Qingzhou.
"This old man is Abby Baker, the leader of the American team. How can I put it? He is very powerful. He is a top expert in particle physics, but he is a bit mean."
As he spoke, he looked at the woman on the podium.
"That woman is his student, Mia Lane. She is the true biography of Abby Baker. She is a very powerful person."
Xu Qingzhou couldn't help but take another look at the woman talking to the staff on the podium. She was less than 30 years old, had a little freckles, and had no expression on her face - comparable to the aloof Song school beauty.
The reason why I was interested was that I had heard of this woman's name. At that time, this person was already a world-class particle physicist.
Mia seemed to notice someone observing her, and looked over.
Well, it's the man named "Xu Qingzhou" from Xia Kingdom.
Mia's eyes were cold, but there was no pressure on people like Xu Qingzhou who had been threatened by Song Yao's death gaze countless times.
The two people's eyes met briefly in the air, and then they each did their own thing.
There were still 10 minutes left before the meeting started. Xu Qingzhou took out his mobile phone and chatted with Song Yao. Xu Qingzhou: "Busy?"
Song Yao: "I'm not busy, just read a book at home."
Song Yao: "Photo\jpg."
In the corner of the desk, the second cat was lying lazily, continuing the sunbathing he had done in Yandong Garden.
Xu Qingzhou: "No, I want to see yours, so that I can make up for the pain of lovesickness."
It took 2 minutes.
Song Yao: "Photo\jpg"
Oh, it's interesting that what she wears at home is still her high school uniform.
Xu Qingzhou clicked his tongue and clicked to save. At the same time, he thought about asking Song Yao to take this set of clothes back.
Xu Qingzhou: "It took you so long to post the photo. Did you go to the mirror to sort it out?"
Song Yao said nothing and pretended to be dead.
Xu Qingzhou: "We are already an old married couple, so why do we still need the baggage of idols? I have seen them look so slovenly."
Song Yao: "Fist\jpg."
If he were around, he would probably be beaten by Song Yao.
After chatting with Song Yao for 10 minutes, Xu Qingzhou put down his phone and opened his notebook when he saw that Mia was already adjusting the microphone on the stage.
"Good morning, gentlemen and ladies."
After saying hello, Mia went directly to the topic: "First of all, I will explain the overall structure to everyone. We all know that the background problem is the main obstacle to two-photon channel analysis."
Mia's voice echoed in the lecture hall. Xu Qingzhou also had a general understanding of the American team's plan. From a framework perspective, the methods used by the other party had many overlaps with theirs.
For example, in the initial part, because the background yield is often much higher than the signal yield, everyone needs to accurately select events at the beginning.
Next, appropriate data-driven methods are used to evaluate the level of background generation.
For background issues, 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 of physical tools and mathematical tools.
For example, the signal model building methods used when building 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 when suppressing background events, while the Xia Guo group used the superposition principle of quantum mechanics and the probability amplitude addition rule.
"Renormalization group theory."
Xu Qingzhou squinted his eyes and did not continue to listen. Instead, he picked up his pen and concentrated on calculations.
The renormalization group is a mathematical tool for examining changes in physical systems at different length scales. The physical effect is to deduct the background and use truncation techniques to set the upper limit of the integral to a certain finite value. It is used to deal with microscopic differences in experimental data. eliminate interference divergence problems and improve the accuracy of measurement results.
In addition to quantum field theory and particle physics, this theory is now used more in condensed matter physics.
The reason why Xu Qingzhou focuses on this is simple: for now, the theory of renormalization groups is actually imperfect.
It seems that it was corrected after seven or eight years.
If this theory is used, it is very likely that the mass of the Higgs particle will change as the energy scale changes.
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 deep in calculations, the expressions of Academician Yang and others next door were a little solemn. Their mood was like a roller coaster. They were still happy that the plan was stable last night.
Who knew it would take a turn for the worse today.
The American team's plan is very complete. Even if they look at it with a very critical eye, they can't find any big problems so far.
Compared with their plan, it is basically a 50-50 split.
With similar plan completion levels, the Xia Guo group's chances of winning are not great. After all, the relationship between the United States and European countries goes without saying.
60 minutes.
After Mia's plan report meeting ended, she looked around and asked: "Do you have anything to add?"
Everyone in the conference room was talking quietly, but including the CMS experts in front of them, they all shook their heads slowly and said "perfect".
Professor Baker smiled softly. He was not surprised by this scene. However, although he said it very casually in front of the Xia people, in fact the whole group was still busy for several days.
After the plan came out, he demonstrated it himself a dozen times.
I am very sure that there is no problem with this plan.
Be arrogant but don't underestimate the enemy, especially when facing the Xia people.
Mia glanced around again to see if anyone asked questions. This time she focused on the direction of the Xia Guo group. Her gaze was dull but very provocative, waiting for her competitors to find loopholes.
Academician Yang shook his head and sighed helplessly, fearing that he might miss out on taking the lead in the initial experiment.
Zhang Changqing and others had bitter expressions on their faces. Although they were very reluctant, they also shook their heads.
Mia's eyes paused and fell on the young man on the side who was engrossed in writing something.
However, the other party was very serious and did not ask for her attention at all.
The result is no longer in doubt.
Seeing everyone shaking their heads, Mia closed her notebook and prepared to give her final thanks and leave the stage.
"Wait a minute, I have a little question."
At this moment, a sudden voice sounded in the conference room.
In an instant, everyone's eyes followed the direction of the sound, and what came into their eyes was a face that still looked childish from the Xia country.
Mia was also stunned for a moment and put down the notebook in her hand.
"Hoo~"
Xu Qingzhou let out a long breath, looked at the manuscript paper in front of him, and thought to himself, hurry up and hurry up, and finally caught up.
The most surprising thing should be Academician Yang and others around Xu Qingzhou, whose expressions were a little surprised.
They had all been mentally prepared. After all, things like literature can turn defeat into victory based on subjectivity. But for research, 1 is 1 and 2 is 2.
Moreover, although I am very reluctant, it is normal to lose and win. In the experiment in March, the Xiaguo group won the British group.
There is a common doubt in their minds: What's wrong with Xu Qingzhou?
Xu Qingzhou has already spoken:
"Regarding the renormalization group, the third part of the report is shown on page 45, point 9, the formula \frac{dm_H^2}{d\ln\mu}=\alpha\cdotm_H^2+\beta\ cdotg^2.”
"By numerically solving the renormalization group equation to obtain the variation curve of MH^2(λ) with λ, have you tried substituting the Higgs particle Yukawa coupling constant."
(End of chapter)