Into Unscientific

Chapter 411 The most important achievement of high energy physics after the founding of the People's Republic of China. Birth! (superior)

After introducing the B1 laboratory hall to everyone.

Ji Xiangdong took everyone to visit B2, C1 and other special experimental sites.

After all, a lot of equipment still needs to be debugged, and the re-inspection process cannot be started immediately.

Secondly, some experimental areas of Jinping Laboratory are indeed quite special, and many of them are special equipment for dark matter.

Even if 90% of the people present are academicians, they don't have many opportunities to come into contact with these things on weekdays-this principle is also applicable in reverse.

For example, Academician Pan and the others often use the Bell-state integrated observation ring. Ji Xiangdong guessed that he didn't even understand how to display the data.

Of course.

Elder Wang's elderly meritorious service did not accompany him, but was placed in the lounge for a rest.

that's all.

About an hour later.

Only then did Ji Xiangdong bring a group of old academicians back to the equipment room behind the B1 laboratory.

This equipment room belongs to the research module of the B1 laboratory. It has a lot of electronic equipment and is mainly responsible for the input of various password schemes.

The area of ​​the equipment room is about 300 square meters, and it looks very spacious. There is a huge LED screen on the middle wall.

Below the screen is a main console, which is almost a 2X8 specification.

usually.

There should be some computers and other equipment under the stage in this arrangement, just like the command room for satellite launches that you usually see.

However, considering that there are many big bosses present today and they are older, the laboratory removed those tables.

Instead.

There are some ergonomic chairs and even recliners.

At the same time, blankets, tea, and some small snacks or porridge with low sugar content are also prepared on each chair.

Other than that.

Outside the laboratory, there is also a group of experts supported by Rongcheng, all of whom are senior leaders from the Health Bureau.

Further out there are even helicopters ready to take off.

After all, these are a total of twenty-seven Chinese academicians, including national treasures like Mr. Wang, so you can't be too careful.

soon.

Most of the academicians sat down and drank tea leisurely.

A few bigwigs in the field of liquid flash came to the console and heard about the experimental plan nearby.

After all, like Hou Xingyuan, they were notified of the discovery of dark matter by the University of Science and Technology only yesterday, and immediately rushed to Rongcheng by plane.

That is to say, they only know about such a thing, but they don't understand the specific discovery process.

Only a top-level meritorious service like Mr. Wang would have grasped all the details of the whole matter before arriving in Rongcheng.

"The whole thing is the earliest, it can be traced back to October last year."

Since there were many bigwigs present at the scene, Academician Pan acted as a commentator without hesitation, pointing to Zhao Zhengguo beside him and said:

"At that time, Academician Zhao conducted an experiment on the decay parameters of the Λ hyperon, and the degree of polarization reached 27%, which was the first breakthrough in the world, and the code name was 4685."

Zhao Zhengguo nodded upon hearing this, and added:

"Well, that was the second decay experiment I led the team to do. I didn't expect any good results at the beginning, but I didn't expect to make a breakthrough for the first time. I'm ashamed."

I heard this.

An old academician from the Huaxia Institute of High Energy Physics thought for a moment and nodded slightly:

"I have the impression that Xiao Zhao sent the newsletter to me that day. If I remember correctly, it rained very comfortably that day."

Zhao Zhengguo recalled it for two seconds, and then nodded his head:

"Oh yes, there was such a rain that wet the cushions of my little eDonkey, and I borrowed a towel from the security office before returning home smoothly."

There was a burst of good-natured laughter all around.

Then Academician Pan paused, patted Xu Yun's shoulder next to him, and pushed him forward:

"Then my student calculated the probability orbit. After the experiment, we discovered the associated particle of the 4685Λ hyperon, and named it an isolated point particle."

"And then there's ground state processing, and..."

After Academician Pan introduced the whole matter eloquently, many academicians looked at Xu Yun in a different way.

These old academicians are generally not young, starting at the age of sixty or seventy, and there are several at the age of ten.

Their intersection with the Internet is basically querying or publishing papers, journals, or at most teleconferencing.

Therefore, whether it is imidacloprid or the previous price war smear incident, not many people know about it.

So from the beginning.

They thought that Xu Yun was just a junior brought by Academician Pan, mainly to guide him to make him look familiar in front of many big shots.

The result was unexpected.

Xu Yun made an unexpected contribution in the whole thing?

The thing about particle orbits was explained earlier. Although it bears the name of "orbit", it is actually a probability model.

This kind of probability model cannot be guessed by guessing alone. It must have strong computing power and observation ability.

For example, the reason why Mr. Ding Zhaozhong was able to discover gluons was because of the reduction calculation of the color and taste of the bottom quark on the spray column.

At that time, his calculation lasted for eight hours, and finally locked the elementary particle that had not been discovered at that time.

Therefore, this particle orbit cannot be handled by anyone - not to mention that Xu Yun is still so young.

Several academicians who are still leading the project can't help but think of the students in their research group.

Although everyone who can enter the sect of these big shots is a genius, they obviously can't do this.

Academician Pan has accepted a good student

Of course.

This emotion is almost fleeting and lasts for a short time.

After all, the academicians who were able to be present had the most contact with geniuses in their lives, and in their eyes, geniuses could be described as crucian carp in the river.

At most, Xu Yun at this time just made their eyes shine, and that's all.

Compared with Cao Yuan and others, Xu Yun is still far behind—at least on the surface.

So soon.

Everyone still focused on the preparations for the verification link.

Gululu——

Following Ji Xiangdong's operation.

The water-based liquid scintillator began to be filled through the pipeline in the hemispherical detector on the ground floor of the B1 laboratory hall next door, which looked like an upside-down bowl.

This is preparing for the subsequent pure xenon.

Students who were dark matter in their previous life should know.

Although there is no standard weak interaction for dark matter, there is a special case that is not included.

That is the xenon atom.

Xenon is an inert gas, and its well-known application should be common in the semiconductor field.

But in fact.

The liquid xenon after the liquefaction of xenon gas is actually an extreme matter that will weakly interact with dark matter.

The density of liquid xenon is very high, about three kilograms per liter, denser than aluminum.

When the dark matter has a weak interaction with the xenon nucleus.

The xenon nuclei undergo nuclear recoil, and the momentum of the dark matter is transferred to the xenon atoms.

The xenon atoms will thus reach an excited state, forming a dimer, accompanied by a small amount of electrons being ionized.

These electrons drift to the gas-liquid surface under the action of an electric field, eventually forming the phenomenon of electroluminescence.

There are two main reasons why this reaction is not considered an ordinary weak interaction.

One is that the hit rate of dark matter is 1/100000000000000000000—this is not a random value, but a real probability.

Second, it is very difficult to obtain pure xenon.

At present, there are 100 countries that can produce pure xenon with a purity of more than 99.00%, but the countries that can produce 99.98%

There are and only five:

Neon, Across the Sea, Teddy Bear, Rabbit, and Sweden.

Well, Sweden.

so what.

At present, the framework of weak interaction basically does not discuss the case of pure xenon—because the framework of the properties of dark matter we talk about is the category of life, and the accuracy is different.

It takes a long, long time to pour 4,000 tons of water-based liquid scintillator.

Therefore, taking advantage of the gap, Ji Xiangdong introduced the specific experimental plan to everyone - so many bigwigs came to Jinping not only to watch the show, but also to audit the error of the experiment.

"Academicians, our preparations are like this."

The side of the operating table.

Ji Xiangdong held a writing board and quickly drew a schematic diagram on it:

"Normally, when atoms de-excite, photons are produced, so a photon detector is placed at the bottom of the device to receive the direct flash signal."

As Ji Xiangdong said, he drew a circle on [Direct Flash Signal].

At the same time, a letter is marked on the side:

L1.

Then he paused, and continued:

"But considering the interaction between dark matter and liquid xenon, transferring energy is a very complicated process, and it cannot be so smooth."

"So we set up another electric field between the gas-liquid surface and the photoelectric tube on top of the detector."

"The strength of this electric field is 10,000V/cm. Under this strong electric field, electrons are accelerated to bombard xenon atoms, so that the electroluminescence phenomenon can be accepted by the photoelectric effect tube on the top."

"The signal received by the top photoelectric effect transistor, we call it L2."

"With these two sets of signals, you can basically determine the final outcome."

Ji Xiangdong's introduction is in human words. Wrong, the popular explanation is

Put a basin of water, and then stuff isolated particles into it, if it shines, it is dark matter.

Of course.

This is just a metaphor, in reality it is much, much more complicated than that.

After Ji Xiangdong finished his introduction.

The old academician from the Huaxia Institute of High Energy Physics who had reviewed Zhao Zhengguo's newsletter before thought about it and asked a question:

"Xiao Ji, the plan is feasible, but how to eliminate the influence of the radioactive background?"

"Although the environment of Jinping Laboratory is very 'clean', there will still be some ordinary radiation that will produce electromagnetic interactions, thus emitting radiation signals."

"Whether it is a dark matter signal or an emission signal, the carriers are photons, and the observation equipment doesn't care what their source is."

"It's okay to study other matter, but the particularity of dark matter is there, so this kind of error must be avoided."

Hearing what the old academician said.

The rest of the people also nodded approvingly.

The old academician's full name is Zhou Shaoping, and he is almost 85 years old this year. He is a well-deserved trailblazer in China's high-energy physics.

What he said about the radioactive background was not a nitpick, but a problem that must be considered.

After all, their verification data today may be related to the most important achievement in the high-energy field since the founding of China, so one cannot be too cautious.

Ji Xiangdong obviously thought of this a long time ago, and calmly continued to explain on the writing board:

"Mr. Zhou, we have also considered the situation you mentioned, and the laboratory has prepared a set of countermeasures in advance."

"As you said, ordinary radiation has electromagnetic interactions, so it reacts more with the extranuclear electrons of xenon atoms and less with the nuclei of xenon atoms."

"So they mostly recoil electrons from the xenon atoms, so for a certain period of time, the L1 signal will have fewer counts."

"So we are going to start from here, and use the ΛCDM algorithm to compare the staged difference between L1 and L2, so as to distinguish the dark matter signal from the ordinary emission signal, thereby reducing the influence of the radioactive background."

"ΛCDM algorithm?"

Zhou Shaoping repeated the word, and couldn't help frowning slightly.

The so-called ΛCDM.

Its reading method is actually Λ-CDM, which belongs to a model of quantum field theory.

The Λ in ΛCDM represents dark energy, and CDM represents cold dark matter.

Quantum field theory, developed in the 1960s and 1970s, explained the elementary particles that had been discovered at that time in a very concise form.

Until the discovery of the Higgs boson in 2012, all the particles predicted by the Standard Model have been discovered, and the deviation between some predictions of quantum field theory and experimental results is even less than one part in a billion.

However, as a dark matter scenario model extended by quantum field theory, ΛCDM is relatively stretched.

Up to now.

The error between it and the description of the existing universe model is about 3%.

In the microscopic field, this is actually not a small difference.

no way.

The scientific community's understanding of dark matter is too shallow.

More critically.

It was said above.

In the liquid xenon scenario, dark matter has a hit rate of 1 in 100000000000000000000.

The model itself has errors, and the hit rate is uncertain.

Therefore, Ji Xiangdong's so-called 'period difference' is basically a false proposition.

for example.

If the model is correct and the hit rate is high, there should be such a result:

The report is divided into 20 intervals, and there is a peak every 4 intervals - that is, a collision has occurred.

The period is fixed, and it is enough to compare the peak difference at that time.

However, due to the incorrect model, the actual result may be as follows:

There are still 20 intervals, 1-4 intervals are smooth, 5 intervals have a bulge, then 6-14 are all smooth, 15 and 17 have bulges.

Without periodic peaks and troughs, it is almost impossible to eliminate the influence of the radioactive background.

So although this solution is feasible, it is definitely not very accurate-at least not worthy of the precision that the concept of dark matter should have.

These bigwigs gathered here today, clearly showing an attitude from above:

Dark matter must be retested as soon as possible, and then published.

Zhou Shaoping didn't understand the reason behind it. Maybe it was Hou Xingyuan's impromptu idea after he learned from Academician Pan that they wanted to come to Jinping, or maybe it was some other idea from a higher level.

Anyway, that's the reality.

Therefore, there is no possibility for them to use ordinary means to verify a round first, and then conduct a more precise re-inspection after a month or so-what they are doing now is the final exam.

Otherwise, if you want to complete the ordinary re-examination, you don't have to spend so much trouble.

Think here.

Zhou Shaoping couldn't help looking at Ji Xiangdong, and asked him:

"Xiao Ji, can this part of the plan be optimized a little bit?"

Ji Xiangdong pondered for a moment, with a look of embarrassment on his face.

It is clear.

Zhou Shaoping obviously couldn't solve this problem for a while.

This is not to say that Ji Xiangdong is not capable enough, or that the Jinping Laboratory, a country's most important tool, is at this level.

It's because the lone particle is so special.

mentioned before.

Currently the hottest dark matter candidate in the industry has two particles.

One is inert neutrinos—ordinary neutrinos are hot dark matter, so “lazy” neutrinos should theoretically meet the requirements of cold dark matter.

The second is WIMP.

WIMP perfectly fits the supersymmetric model, and the theory is quite beautiful, which has convinced most physicists.

correct.

When introducing WIMP before, I once said that there is an old professor in the Academy of Sciences who likes fairy tale novels very much, and gave WIMP the nickname "Tao Biao".

This person is Zhou Shaoping.

all in all.

Since this thing is so suitable in the model, countless of the best experimental physicists in the world have been looking for dark matter along this direction for decades.

The results of it?

HKUST discovered a lone point particle quietly, and at the same time, due to the accompanying nature of the 4685Λ hyperon, it is completely different from all previous research directions.

When this situation falls into reality, the most intuitive reaction is.

Many devices that were previously WIMPs are suddenly useless.

If there is enough time, it’s okay to talk about it. The big deal is to debug the equipment by brainstorming and debugging, and maybe it will be used in a month or two.

But don't forget.

It took more than 20 hours for Jinping Lab to receive the news.

At the same time, due to the particularity of dark matter, it is impossible for the Academy of Sciences and even higher authorities to give so much time to prepare—otherwise, everyone would not rush to Jinping.

in this case.

You want the lab to come up with a plan that is complete and seamless without any errors

It might as well ask them to tinker with colorful black.

Actually.

The plan proposed by Ji Xiangdong alone caused more than a hundred scientific researchers to lose most of their hair.

Zhou Shaoping and others soon realized this, and then...

The eyes of several old academicians lit up immediately.

The more capable a person is, the more he refuses to obey his old age.

As veteran researchers, they have been looking forward to their contribution almost from the moment they arrived at Jinping's underground laboratory.

It's just that this is Ji Xiangdong's home court, so it's obviously not appropriate to speak rashly.

And there are flaws in the current plan, isn't this a great opportunity?

After all, one of the names of their trip is to serve as an external consultant for the verification plan.

In fact, what Ji Xiangping said before may not be without the idea of ​​asking these big shots to help.

So soon.

A group of gray-haired academicians gathered around the table and began to discuss the experimental plan on the spot.

After the discussion started.

Zhou Shaoping first threw out an idea:

"Everyone, we have limited time, so I'll just throw a brick to attract someone - my idea is, can we start with the strong PC problem?"

"Strong PC problem?"

Hearing Zhou Shaoping's words, another old academician with a heavy Sichuan accent frowned:

"Zhou Laosi, isn't that the category of the strong nuclear force?"

"That's right."

Zhou Shaoping nodded lightly, but quickly said:

"But Lao Chen, don't forget that there is a Peccei-Quinn metric in the strong PC problem, which is in line with the dark matter model"

The old academician surnamed Chen was slightly taken aback, and then patted himself on the head:

"mmp, why did I forget that thing?"

Strong PC problem.

This is a complex content of quantum chromodynamics, so there is no need to go into details.

all in all.

The "strong" here corresponds to the strong nuclear force, and CP refers to Charge Parity, that is, charge-parity.

Students who are familiar with advanced physics should know it.

Many problems in advanced physics often have different solutions in different situations, and these solutions have a unified name:

metric.

The most famous is Einstein's field equations.

At present, there are several metrics for Einstein's field equations, such as Kerr metric, Schwarzschild metric, etc.

At the same time, these metrics will also correspond to a certain model.

For example, the Kerr metric corresponds to the Kerr black hole.

The Gödel metric corresponds to the Gödel universe and so on.

Incidentally.

There is also a special space-time metric for Einstein's equation, which is called Alcubieri metric.

It is the "bubble curvature engine" often mentioned in science fiction films.

The weird thing about this thing is that its concept first appeared in science fiction films, and then Alcubieri came up with this solution in 1994.

That is to say, fantasy comes first and theory comes later.

Did science guide sci-fi, or did sci-fi inspire science?

alright.

The topic returns to the original place.

Just like the metrics mentioned above.

The Peccei-Quinn metric is also a specific solution to the strong PC problem.

This is the Peccei-Quinn mechanism proposed by Peccei and Quinn in the 1970s. Helen Quinn is also the most promising female physicist to win the Nobel Prize in High Energy Physics.

Under a certain energy level, it can construct a test framework for dark matter, and the supersymmetric partner also conforms to the characteristics of the 4685Λ hyperon.

At the same time, it can adjust the scattering angle and eliminate errors through the most reliable optical path difference.

Of course.

The Peccei-Quinn metric also has some technical difficulties, and whether it is feasible or not needs to be discussed in more detail.

What these academicians have to do now is to roughly screen out some relatively feasible plans first, and then screen them one by one.

So soon.

Many academicians continued to start a new round of brainstorming:

"In addition to the Peccei-Quinn metric, I think it would be a good idea to let charged particles cross the TPC."

"How about using deuterium in heavy water to detect neutrinos like Kamiokande? There should be a lot of heavy water here in Xiaoji."

"How about ionization plus phonons?"

"I think the CQ mechanism we used to engage in Gundam is feasible."

After more than an hour.

Five candidate plans were put before everyone:

Peccei-Quinn metric.

9 kg of Ge targets.

Detecting the effect of dark matter on atomic clocks.

Further capture the secondary particles of dark matter.

as well as

Allowable errors exist, and the fitting analysis is carried out through the measured curves.

Then soon.

The scheme of secondary particles was first ruled out.

Secondary particles belong to the category of indirect detection, and its principle is very simple:

It is to let the secondary particles of the dark matter particles interact with the detector, so as to indirectly obtain the information of the dark matter particles.

Just like the mother is the dark matter particle, and the child is the secondary particle produced by the decay of the dark matter particle.

According to the first law of the thimble, the child is saved by the mother.

Next.

Scientists use cameras to take pictures of children, and use the children's appearance to infer the mother's appearance backwards.

This approach is a way of thinking in conventional research, the difficulty is relatively low, and it is very interesting.

But in the current occasion, it is obviously not suitable.

Then soon.

The second and third options were also ruled out.

These two schemes are equally difficult to reduce the influence of the radioactive background, and have little practical effect.

Therefore, there are only two options left in front of everyone:

Retests were performed using the Peccei-Quinn scale model.

Or allow errors to exist, and conduct fitting analysis through multiple rounds of measured curves.

Then

There were serious differences in the opinions of the people.

Among the 27 academicians.

Except for Wang Lao, Zhang Lao and Hou Xingyuan who did not express their views, the academicians who supported the two proposals were equally divided.

"Guys, I stick to the Peccei-Quinn metric."

Zhou Shaoping first took a sip of the tea on the table, then looked around, and then continued:

"The hit probability of 1/1000000000000000000000000000000000000000000000000000000000 by far is too low. I don't think a normal curve can be fitted through multiple measurements."

"Even if we do 100,000 experiments a day, the decimal point is still less than ten."

"This kind of plan is not so much to eliminate errors, but to hypnotize oneself."

After Zhou Shaoping finished speaking, the people around him reacted differently.

Some academicians nodded in agreement.

Some academicians were expressionless.

Some academicians frowned, obviously holding opposing views.

after awhile.

The only female academician on the scene spoke:

"Old Zhou, that's right. Everyone knows that the Peccei-Quinn metric is obviously more appropriate."

"But the question is... how do we construct a wide-area gauge field configuration?"

"There are now more than a dozen genres in the axion field alone, not to mention the strange particle of the solitary point particle."

"If you can't even show the breaking field, no matter how applicable it is in theory, it's just a spectacle in reality."

Zhou Shaoping pinched the bridge of his nose a little annoyed when he heard this.

The situation that the female academician said is also the core of the different opinions of the people present.

Everybody knows.

The Peccei-Quinn metric or the Peccei-Quinn energy scale is obviously of great help at the moment.

but the problem is

The framework of dark matter established by it is more inclined to the axion field.

Although it can control the exit angle θ of the particles, the upper and lower signal receivers can avoid the error of the radioactive background through the optical path difference.

But for isolated particles, it is very troublesome to construct a wide-area gauge field configuration.

This is not a problem that can be solved with a little more time. It involves the local u1 symmetry of the gauge field extended from Maxwell's equations.

At least during the discussion just now, no one could think of a suitable tangent point—or that sentence, everyone is too unfamiliar with the solitary point particle.

Looking at Zhou Shaoping with an uncertain face, the female academician comforted her again:

"Old Zhou, I think you have fallen into a certain misunderstanding."

"The probability of multiple fittings is indeed not high, but the conditions of Jinping Laboratory itself are very good. The so-called influence of the radioactive background is actually not a large base."

"If we can build a suitable gauge field, then of course we can use this idea, but right now"

Zhou Shaoping remained silent.

What the female academician said made sense, and he naturally knew it.

But as a physical person from the last century, Zhou Shaoping or all rabbits have a kind of obsessive-compulsive disorder:

If we want to do it, we must do the best, so good that others can't find faults.

Then he gritted his teeth, still not ready to give up:

"We can start the calculation now. Jinping's equipment is very advanced, and there may be results in a short time!"

Hear what he said.

Another academician who had previously opposed it shook his head, and his tone was also very frank:

"Old Zhou, it's okay to give you some time, but what about the train of thought?"

"If you want to calculate and build a wide-area field, you must have a way of thinking, right?"

"Such as how much the flash liquid weighs, whether to add isotopes, the direction of the field strength, and most importantly, how it interacts with dark matter—is it collision, annihilation, or sliding?"

"It's not that everyone is against you. If you can come up with a suitable idea, I will be the first to beat you with this old bone!"

"."

Hear this.

Zhou Shaoping opened his mouth, but in the end he still didn't make a sound.

After all.

still not reconciled

Looking at the silent Zhou Shaoping.

Hou Xingyuan on the side shook his head, ready to speak to make the final decision.

If you can't do some things, then you can't blame others for choosing other ways.

This is a very realistic truth.

However, just when Hou Xingyuan was about to give up.

In the area on the left side of the scene, a voice suddenly sounded weakly:

"That. Academician Zhou, if you use the Peccei-Quinn metric, you can try it without the angle of double electron capture."