MTL - Into Unscientific-Chapter 411 The most important achievement of high energy physics after the founding of the People's Republic of China... was born

  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 the direction of dark matter.

  Even if 90% of the people present are academicians, they don’t actually 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.

  The elderly Wang Lao did not accompany them, but were placed in the lounge for a rest.

that's it.

   About an hour later.

  Ji Xiangdong took 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 bosses present today and they are older, the laboratory removed those tables.

Instead.

   are some ergonomic chairs and even recliners.

  At the same time, blankets, tea, and some small snacks or grain porridge that are not very high in sugar are 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.

   There are also several experts in liquid flash who came to the operating table and heard about the experimental plan nearby.

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

   That is, they only know about this matter, but they don't understand the specific discovery process.

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

   "The earliest thing about it can be traced back to October last year."

  Because there were many bigwigs present at the scene, Academician Pan did his part to act as a commentator, 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 the first breakthrough. I'm ashamed."

   Hear this statement.

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

   "I have an impression of this matter. 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 cushion 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."

   "Then it's ground state processing, and."

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

  These old academicians are generally not young, starting at the age of 60 or 70, and there are several in their 10s.

  The intersection of them and the Internet is basically querying or publishing papers and journals, and at most it is teleconferencing.

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

   So from the beginning.

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

   The result was unexpected.

   Xu Yun made an unexpected contribution in the whole thing?

  Particle orbits have been 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 flavor 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.

   There are several academicians who are still leading the project, and they 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. In their eyes, geniuses can be described as crucian carp in the river.

  Xu Yun at this moment is at best to impress their eyes, and that's all.

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

   So fast.

   Everyone still focused on the preparations for the verification link.

   Gululu—

  Follow Ji Xiangdong's operation.

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

   This is preparing for the subsequent pure xenon.

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

  Dark matter does not have the standard weak interaction, but 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 nucleus will undergo nuclear recoil, and the momentum of the dark matter will be transferred to the xenon atom.

  Xenon atoms will thus reach an excited state, forming a dimer, and at the same time, a small amount of electrons will be ionized.

  These electrons drift to the gas-liquid surface under the action of electric field, and finally form electroluminescence phenomenon.

   This reaction is not considered an ordinary weak interaction for two main reasons.

  One is that the hit rate of dark matter is 1/100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 of of which are not random numbers, but the real probability.

  Second, it is very difficult to obtain pure xenon.

  Currently, 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 one and only five:

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

   Well, Sweden.

so what.

  Basically, the current weak-action frame will not discuss the case of pure xenon—because the frame of the property of dark matter we are talking 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.

  Thus, 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 preparation is like this."

  Beside the console.

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

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

  Ji Xiangdong said, and 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 effect tube on top of the detector."

   "The strength of this electric field is 10000V/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 tube, we call it L2."

   "With these two sets of signals, the final result can basically be determined."

  Ji Xiangdong’s introduction is in human words. It’s 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 fact it is much, much more complicated than this.

   After Ji Xiangdong finished his introduction.

  The former academician from the Huaxia Institute of High Energy Physics who had reviewed Zhao Zhengguo’s newsletter 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 if we 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 full name of the old academician is Zhou Shaoping, and he is almost 85 years old this year. He is a well-deserved trailblazer of Huaxia High Energy Physics.

  The radioactive background he mentioned is not picking a thorn, 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 we 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 the xenon atom and less with the nucleus of the xenon atom."

   "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, so as to reduce the influence of the radioactive background."

   "ΛCDM algorithm?"

   Zhou Shaoping repeated the word, and his brows frowned slightly.

  The so-called ΛCDM.

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

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

  Quantum field theory was developed in the 1960s and 1970s, and 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.

  But 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 scenario of liquid xenon, the hit rate of dark matter is 1/100000000000000000000.

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

  So Ji Xiangdong's so-called 'period difference' is actually 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.

  But due to the incorrect model, the actual result may be like this:

   Still 20 intervals, 1-4 intervals are smooth, 5 intervals have a bump, then 6-14 are fully smooth, 15 and 17 have bumps.

  There are no periodic peaks and troughs, and it is almost impossible to eliminate the influence of 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 announced.

   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.

  In short, the reality is like this.

  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 need 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?"

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

It is clear.

   Zhou Shaoping's question obviously cannot be solved 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.

   But because the solitary particle is too 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 Xianxia novels very much, and gave WIMP the nickname [Tao Biao].

   This person is Zhou Shaoping.

all in all.

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

The results of it?

  HKUST discovered a lone point particle quietly. At the same time, due to the associated 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 WIMP suddenly became useless.

   If you have enough time, it’s okay to say something. At worst, let’s work together to debug the equipment, and maybe it will be available in a month or two.

   But don't forget.

   It took more than 20 hours for Jinping Laboratory 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 laboratory to come up with a complete and seamless plan without any error

  Then it might as well ask them to tinker with colorful black.

   Actually.

  Ji Xiangdong's plan 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 suddenly lit up.

  The more capable a person is, the more disobedient they are.

  As veteran researchers, they have been hoping to contribute something almost from the moment they arrived at the Jinping underground laboratory.

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

   And the current plan has flaws, 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.

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

   So fast.

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

   After the discussion starts.

   Zhou Shaoping first threw out an idea:

   "Guys, 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 what Zhou Shaoping said, another old academician with a heavy Sichuan accent frowned:

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

   "Exactly."

   Zhou Shaoping nodded slightly, 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 issues.

   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 ChargeParity, which is charge-parity.

  Students who are familiar with advanced physics should know.

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

   Metrics.

  The most famous is Einstein's field equations.

  Currently 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.

  Gödel's metric corresponds to the Gödel universe and so on.

Incidentally.

  Einstein's equation also has a special space-time metric, called Alcubieri metric.

  It is also 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, fantasy comes first and theory comes second.

   Did science guide science fiction, or did science fiction inspire science?

All right.

  The topic returns to the original place.

   Just like the metrics mentioned above.

  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.

  It can construct a dark matter inspection framework at a certain energy level, 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 fast.

  Many academicians continued to start a new round of brainstorming:

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

   "How about using deuterium in heavy water to detect neutrinos like Kamioka? 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."

   More than an hour later.

  Five candidate plans were put in front of everyone:

  Peccei-Quinn metric.

  Only 9 kg of Ge targets.

   Detect the effect of dark matter on atomic clocks.

   Further capture the secondary particles of dark matter.

as well as

  Allow errors to exist, and conduct fitting analysis through multi-theory measured curves.

   Then soon.

   Secondary particle solutions were first ruled out.

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

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

  It’s 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 deduce the mother's appearance.

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

   But in this occasion, it is obviously not suitable.

   Then soon.

  Plans 2 and 3 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 before everyone:

  Retested with Peccei-Quinn scale model.

   Or there is an allowable error, and the fitting analysis is performed through multiple rounds of measured curves.

Then

  People's opinions have serious differences.

   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 1/10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000000000000 isn’t very 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 scheme 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 are expressionless.

   Some academicians frowned, obviously holding opposing views.

after awhile.

  The only female academician on the scene spoke:

   "Old Zhou, you are 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 get the breakout field, no matter how applicable it is in theory, it's just a spectacle in reality."

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

  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 by Maxwell's equations.

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

  Looking at Zhou Shaoping whose face was cloudy and uncertain, the female academician comforted 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 continued to remain silent.

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

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

   To do it, we must do the best, so good that no one else can find fault.

   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!"

   Heard what he said.

  Another academician who was previously opposed 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?"

   "For example, how much is the weight of the flash liquid, whether to add isotopes, the direction of the field strength, and most importantly, how to interact 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!"

  “.”

   Heard this.

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

   At the end of the day.

   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 to the left of the scene, a voice suddenly sounded faintly:

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

Note:

  The third day of the 4D update, ask for a monthly pass! !

  (end of this chapter)