Therefore, since the Standard Model was put into use in 1970s, physicists have been trying to surpass it. In fact, they will break the model and experimental data and violate their nearly perfect equations. Then, from its fragments, they must build a new and better theory. The Large Hadron Collider (Composite) is a large particle accelerator of CERN, which is located near the European Particle Physics Laboratory in Geneva, Switzerland. It is the latest attempt to break the standard model-many people think it is a guarantee of success. Huge energy production will force the standard model of particle field to be impossible to implement. Frank Wilt, a theorist at the Massachusetts Institute of Technology in Cambridge, won the Nobel Prize in Physics in 2004. He said that beyond the current situation of competition, "complex things are by far the most popular" and his work is based on the standard model.
However, reorganization is not unique. For decades, physicists have tried to surpass the various methods of the standard model, sometimes the accelerator, sometimes the accurate measurement of thrilling rare events, and sometimes the observation of outer space. After the time complex is fully accelerated-its first results are not expected to appear, at least until next summer (see' Blocking Collider')-some experimental teams think they have a chance to fight and win the first prize. Their task will be difficult: the standard model is an arduous task, resisting all convenient and obvious attacks. In order to fight it, this experiment will require unprecedented sensitivity, a lot of data and a little luck. This is the ruined hero who thinks that he has the most tasks in a few years.
Tai Vatron
Although it is a composite proton acceleration, other heavyweight particle accelerators in the world have broken the standard model for the first time. Since 200 1, Tevatron at Fermilab in Batavia, Illinois has been accelerating protons and antiprotons with an energy of about 1 trillion electron volts.
This is only one seventh of the final energy complex, but the total energy is not the whole of finding new physics. It is extremely rare that the collision will produce new particles outside the standard model, which means that there is no longer an accelerator running and more data accumulation, and there is a better chance to find something. Therefore, at least for a while, Tevatron will continue to have a data-leading complex. Even from summer to 2009, Tevatron's data volume will be several times that of its new competitors.
These data show some attractive, even temporary, beyond the standard model. The measured particles with deviation are called singular B mesons. Hotel is a strange quark and antiquark bottom, which is the heaviest of all mesons. According to the rule called charge parity symmetry, the hotel decay predicted by the standard model acts as its antiparticle (the proposed anti-singular bottom and quark) in the same way. However, the difference between the two prompts and their attenuation are measured. According to Dmitry Denisov, a spokesman for the teva tron D-zero experiment, this difference may be an important clue to find the discovery. This may indicate the existence of new exotic particles or previously unknown principles. Anyway, Denisov said, "This is an exciting measurement."
Robert Rother, a spokesman for Tevatron's other major experiments, the Collision Detector Laboratory or the Civil Defence Force, added that this unusual hotel was not the only weirdo who appeared in the accelerator. The unusual functional decay of top quarks and anti-top quarks aroused his curiosity. He once again admitted that this is far from certain. But some of these signals may be important, Roser said. "When you add one of the data, [these anomalies] can become a reality."
Maybe this is not surprising. A more skeptical view comes from John Ellis, a theorist at CERN. Yes, Tevatron can provide some attractive hints, Ellis said, but it is impossible to make a clear discovery until the complex is strong. He pointed out that particle physics in the world did not constitute a discovery until the measurement of five sigma (the average of five standard deviations), which is equivalent to 99.667% accuracy. More data than Tevatron has accumulated so far will need to meet strict standards, and it is impossible for the detector to achieve these sharp increases before surpassing its new competitors. Ellis said: "I think it will be very, very difficult to make Tevatron." "I just don't want to see the complications they got before they started generating electricity."
universe
Although high-energy physicists gather in the control room of their machines, another group of physicists are looking for heaven. Therefore, they hope to find something that breaks the standard model-if the universe cooperates.
Most importantly, their spacecraft will look for signs that dark matter can make up as much as 85% of the matter in the universe. Astronomers know that dark matter exists not only because of its gravitational influence on the shape of galaxies and the universe; It seems to pass right through ordinary matter found in stars, planets and human bodies. It is speculated that dark matter is a common substance, and even if it exists, there are only a few smoke particles. However, no one is quite sure that these particles are possible-unless they do not occupy the standard mode.
One candidate comes from the "supersymmetry theory", which predicts that each particle is in the standard model and the other is outside the heavier partner model. The lightest supersymmetric companion is called neutralino, and it is expected that the correct property just now is dark matter.
Neutralinos itself is not a telescope, an orbit or anything else. However, on a conventional basis, two neutral partners may collide and disappear-creating a shower that an ordinary particle orbital detector may get. Fu Youde's experiments (antimatter and light nuclear astrophysics) have seen an interesting clue. Satellite propagation tools receive excess anti-electrons, which may have produced dark matter annihilation (see Nature 454,808; 2008). "This is a beautiful result," said Glachet Gelmini, a physicist at UCLA, after seeing the data from the Eastern District. However, she added that complex measurements need to be cautious.
Second, the recently launched satellite can also be used by neutralino, who died at the scene. Fermi Gamma Ray Space Telescope is a $6.9 million space instrument designed to scan the whole sky for ultra-high energy photons. Such gamma rays may be produced by neutral satellite collisions, in which case they will be displayed in the smoke as the sky map of the ubiquitous orbital probe. "This will be an amazing signature," said Steven Holt, a telescope project scientist and NASA Goddard Space Flight Center in Greenland, Maryland.
Turner, a cosmologist at the University of Chicago, Illinois, said that if these signatures are discovered and confirmed in time, there is definitely a chance to defeat complex molecules in the process of seeking breakthroughs in the standard model. However, the hotel pointed out that although astrophysics will take the lead in making such a discovery technically, there is nothing they can do. Antielectrons, gamma rays and other similar signals can only provide physicists with a rough series of large-scale new particles, not to mention how supersymmetry may work. For these reasons, "there will still be many indispensable question marks", saying that the hotel-problem must be solved.
The unstoppable collider
According to Nature, the Large Hadron Collider (LHC) is located near CERN, the European particle physics laboratory, and will soon run the first proton. But there are still many things to be done before the machine is produced and scientific discoveries are released. In the next few months, even if the operators fine-tune the collider itself, other physicists will try to get the ring around the experimental interval up and running.
The size construction of switch detector is a big task. Each musical instrument is thousands of small detectors, and the collision of particles in orbit must be synchronized. The probe is currently entering an experiment to adjust the use of cosmic rays from outer space, said Atlas, a spokesman for Peter Jenny. However, watching real particle collisions will be a completely different problem. Colliding proton beams will produce hundreds of millions of unique' events' every second, and each event includes hundreds or thousands of debris particles flying outward from the collision point. Since the purpose of the detector is to track most or all of these particles individually, the result will be more data than the experimenter can handle. Fortunately, most collisions will happen. This is just an ordinary collision. Therefore, the experimenter has been equipped with an electronic detector "trigger" to separate the other interesting collisions. For example, a simple mark will trigger a collision with particles that produce "muons", which can create decay changes for large-scale particles. Jenny said that each trigger will be designed as an interesting activity to save evidence, and every country must carefully adjust it.
After filtering the data, it must be analyzed. To this end, the data will be sent from experiments to thousands of physicists through large-scale grid computing, which can shuttle PB data, university laboratories and all over the world. Jim Virdee, a spokesman for another major experiment at CERN, the contract muon solenoid (sterile line) experiment, said that the preliminary experiment is progressing smoothly, and Atlas team and sterile line are now drilling with actual data generated by computer.
If all goes well, Jenny and Verdi both say that the result may be in the summer of 2009 at the earliest. By then, the accelerator should have been running at full power of 7 trillion electron volts for several months, and there is still time to sort out any technical problems.
I would like to ask the compound to find some new physics and run it first. It's possible. The machine will collide with particles with about seven times the energy. At present, the world's leading accelerators are located in Tevatron and Fermilab in Batavia, Illinois. Virdee said that this is a huge leap. In principle, new particles can be seen almost immediately. "You don't need a lot of data to test it except what is done in the laboratory," he said.
Physicists at Fermilab suspect that this is an understandable evaluation. Physicists who have worked in Tevatron for two years can fully grasp the characteristics of this experiment, saying
Robert Rother, spokesman of the collision detection laboratory. Dmitri Denisov, a spokesman for Fermilab's D-zero experiment, said that even with higher energy, it would take a lot of collisions to discover new things. "Proton collision and proton center detection are not enough," he said. G.B
dark
Other physicists choose dim light. They watched some highly sensitive detectors from abandoned mines and traffic tunnels in nests, which can find directly labeled dark matter, including supersymmetric neutral partners (see Nature 448,240; 2007).
There are about 50 different schemes of this detector, but they all follow the same basic concept. Take some dark matter that you think you can handle, put it deep underground to protect it from cosmic rays and other destructive effects, and then wait for what will happen. "It's like watching grass roots grow," Wilt Burke said.
Although they may not be the most exciting way to defeat complexity, these detectors are making remarkable progress. In one experiment, Cryogenic Dark Matter Search II, or CDMS II, is currently accumulating data in a mine in Sudan, Minnesota. Its business goal is triple crown, and the current sensitive period is the end of this year. Another experiment needs XENON 100, which is located in the tunnel of the big Sasso Mountain in Italy. Composite detectors can complete the processing of their findings before they have a chance to produce results for the first time at any time. Player Aposiler, principal researcher of XENON 100, new york Columbia University, said: "This field will be very fast and the competition will be fierce. This is not an easy time to survive. "This is a great era."
Coupled with these prospects, a team claimed to have found dark matter in its detector. Earlier this year, the experiment of on-demand distribution /Libra (a rare process of dark matter mass sodium iodide) was also announced in the Big Sasol National Laboratory, and it has seen the signal in its latest generation detector (see Nature 452,965,438+08; 2008). However, they found that other groups were confused. Apostel said that his experiment was located in a cellar next to Distribution on Demand/Libra. She said that no one else has been able to confirm this signal. In fact, the findings of other teams seem to be contradictory. "We certainly won't agree."
Although these detectors seem to be improving the leap-forward development, they have a fatal weakness: they just work, and if the dark matter particles that have not been seen so far interact, at least occasionally and regularly. Ellis said that there is no guarantee in this case. As far as he is concerned, these experiments have created "balls in the dark"
However, Ellis admits that there is a chance that these esoteric searches may try to see the complexity before them. "I think dark matter is a clown's bag," he said.
neutrino
In the next few months, caffeine will be a vague fuel for most of these scientists, who are scrambling to overcome this complexity. But neutrino physicists can do it easily: they have made new breakthroughs that they didn't have ten years ago.
Neutrinos are neutral members of lepton particle family, including electrons. The original version of the standard model predicted that neutrinos should be completely massless, but other experimenters were skeptical. Over the years, they have seen fewer and fewer neutrinos than theoretically predicted. One possible explanation is the deficit, and solar neutrinos can switch from one type to another. However, this transformation is only possible when neutrinos have mass. 1998, the so-called super Kameyaoka, a Japanese experimental missile, saw the action of the neutrino switch, which was the first time-and the only time so far-that the company found that it violated the standard model.
Unfortunately, Ellis said that neutrino mass can be accommodated in the standard model, and only some simple modifications were made to the equation. "It is possible to add some relatively easily," he said. Therefore, although neutrino physics can be said to have won the prize, they found that it was not helpful for theorists to find new physical models.
However, neutrinos may not only be unfinished. Experiments in the United States, Europe and Japan try to emit neutrino beams in their detectors to learn more about how to convert neutrinos from one to another. Randall Lisa, a theorist at Harvard University in Cambridge, Massachusetts, said that the exact details exchange may help narrow the possible scope of the new theoretical model.
And there may be two new detectors. European cooperation is now running an astronomical telescope and a neutrino abyss environmental research (Mars) probe in Toulon, France, on the Mediterranean coast, and a group of Americans are installing an ice cube in Antarctica. At the same time, the string detector is used to see the amazing source of neutrinos in the high-energy universe, such as water or ice. Ann Taris completed it earlier this summer, and about half of the 70 series of detectors in the Ice Cube have been installed. However, according to Francis Haltzen, principal ice researcher at the University of Wisconsin-Madison, ice cubes are more than five times more sensitive than American super temples. "This is not what we thought we could find," he said.
After all, this thing may be used for debate. One possibility is that dark matter particles produced by neutrinos are trapped in the core of the sun. However, Halzen said that everything has been seen, and neutrino experiments almost certainly need a series of complicated follow-up actions. "I think these experiments complement each other," he said. "But if I had a choice, I'd rather see it for the first time."
Success?
So, what is the best standard model for these projects? Wilt expressed doubts about this. "I didn't sit on the edge of the chair," he said. Look at the record, it seems that "the standard mode always wins". He believes that only the complex has a real chance to break the existing model at any time.
And there is no guarantee that even the giant collider will find something new. "Supersymmetry can be displayed at any time before mid-2009, which has never happened before," Ellis said. He said that if there is no date forever, physicists will face "the biggest horror scene imaginable". "What, do we do this?" He asked.
But Turner holds a different view. In the final analysis, these experiments are combined with complex battles. He believes that through their data combination, we can defeat the composite standard model and discover a new physical society. "We are approaching a major revolution," he said.
Jeff Bloomfield is a senior reporter at natural headquarters in London.
To learn more about the opening of the complex, the nature of the visit is especially in the news.