Comprehensive coverage

The particle accelerator that can save physics

An accelerator proposed to be built in Japan may be able to solve the mysteries that the Large Hadron Collider in Geneva was unable to solve

Computer simulation of the proposed ILC particle accelerator. Source: the project website.
Computer simulation of the proposed ILC particle accelerator. source: Project site.

The discovery of the Higgs boson at the "Large Hadron Collider" (LHC) of the European Organization for Nuclear Research (CERN), near Geneva, in 2012, was a spectacular confirmation of the standard model of physics - a theoretical framework that describes all the particles and forces known so far in physics. The Higgs boson, whose existence was first predicted in the 60s, was the last missing piece of the ensemble. But since then, physicists have been stuck. The hope of the scientists to discover through the LHC "superpartners" particles, the discovery of which would help solve problems in the standard model that have been known for a long time, was disappointed and these particles were not discovered.

Physicists have been talking for decades about an accelerator that could find these missing particles. Three years ago, an international team of physicists and engineers completed its design. According to the plan, in the accelerator known as the "international linear accelerator" (ILC), a 31 kilometer long tunnel under the mountains in the area Kitakami In northern Japan, electrons and their antimatter particles, the positrons, will collide. These collisions will cause the ionization of matter and antimatter to release energy on the order of 250 billion electron volts. (A later upgrade will double the ILC's energy output.) At the time of writing this column, Japan's Ministry of Education, Culture and Sports (MEXT) is expected to decide whether to proceed with the ILC project. We think you should.

The standard model had a hole that a Higgs boson with a mass of 125 billion electron volts filled exactly. And this is indeed what the scientists discovered at the LHC. The turning point in the plot is that the physicists do not know how to explain why this is his mass. (Physicists usually measure the mass of particles in electron volts, which are units of energy, because energy and mass are equivalent.) In fact, they've known since the early 80s that virtual quantum effects should make the Higgs boson millions of times more massive or billions.

the theory of supersymmetry, SUSY, offers a solution. It hypothesizes a fundamental connection between matter particles, such as quarks and leptons, and between force-carrying particles such as photons, gluons and W and Z particles. It also predicts a host of new compatible particles with strange names such as squarks (super-compatibles of quarks) and Higgsinos (super-compatibles of the Higgs boson). These compatible particles react with the Standard Model particles in a way that cancels out the virtual quantum effects, so that the masses predicted by the Standard Model and observed at the LHC are obtained.

Physicists had hoped to find these supermatches as early as 25 years ago when the LHC's predecessor, CERN's Large Positron Collider, began operation. They did not find. But when the superconformers didn't show up at the much bigger and more powerful LHC, some physicists were alarmed.

But there is hope. Recent theoretical studies suggest that Higgsino particles may indeed be created at the LHC, but the scientists do not find them in the mix of particles that are emitted in the collisions between protons and antiprotons that occur there.

Computer simulation of a subsurface cross-section of the proposed ILC particle accelerator. Source: the project website.
Computer simulation of a subsurface cross-section of the proposed ILC particle accelerator. Source: the project website.

In this area the ILC should excel. The collisions in it are done at considerably lower energy than in the LHC, but its great advantage is that unlike its European cousin, electrons will collide with positrons. Unlike protons and antiprotons, which are made up of elementary particles and antiparticles, quarks and antiquarks, electrons and positrons are elementary particles themselves. Their collisions are much cleaner, therefore, the higgsino particles that will appear in their wake will be easier to detect.

The cost of building the ILC will be at least $10 billion, roughly double the cost of building the LHC. There is no doubt that this is a high price for any country alone. International cooperation is therefore necessary. And it will also pay off.

According to the theory, the ILC should produce hygsino particles, sleptons (lepton supercorresponders) and other supercorresponders in abundance. If so, the ILC will be able to confirm supersymmetry and verify the subatomic particle model that physicists have long suspected to be correct. Since Hygissino particles may be part of the dark matter found throughout the universe, they could also help solve one of the unsolved mysteries of astrophysics. And if no super-matches are discovered in it yet, even then science will advance, since the theoreticians of the high energies will be forced to concentrate their efforts on other theories. Either way, the insights we will derive can deepen our understanding of the laws of nature, and their implications for the origin of the universe and its development.

About the writers

Howard Barr - Professor of High Energy Physics and holder of the Homer L. Dodge Chair at the University of Oklahoma.

Vernon D. Berger - Professor of Physics and holder of the Vilas and Van Valk Chairs at the University of Wisconsin in Madison there.

Jenny List - Experimental physicist and faculty member at the DESY Institute in Hamburg, Germany.

14 תגובות

  1. "To save physics"... as if without saving physics will be lost... what a scrambled title. Everything, just to work on the reader so that he clicks on the article and the editor can say "120 thousand hits per month"...
    By the way, physics cannot be saved or destroyed. It is only possible to find out the legality of it (for all the "physicists" who quibble).

  2. Haim P,

    No need to put words in anyone's mouth. You wrote in your response that there is a claim in the article or in the title that "something is going to disprove physics", you received a fairly detailed explanation of why this was not said, and why it was intended. The expression "to save physics" is comical and humanizes physics (after all, there is no meaning to "saving" a scientific field). Both I and Shmulik explained to you what is meant - what is the threat or trouble that physics is currently in and why the new accelerator can solve or improve the situation. None of us wrote that the title is accurate. She is after all, as Shmulik tries to say, just an expression. Your need to focus on those three words instead of the message in the article is very puzzling.

  3. I responded to clarify the point of the article because you are entering the subject of refuting physics and that was not the intention of the article at all.
    As for the title, well...flow

  4. Haim P,

    I did not see in the article a claim that something is going to "disprove physics", as you say. The meaning of "saving physics" is twofold:

    1. As written in the subtitle (and explained in sufficient detail in the article itself), there are a large number of problems in theoretical physics that are solved in a simple, elegant and consistent way with the help of supersymmetry. If we fail to discover supersymmetric particles and become convinced that they do not exist, we will be left with a lot of unanswerable problems. A finding of evidence for supersymmetry will turn the currently existing theoretical solutions to these problems into practical solutions.

    2. In order to progress in physics (or in any other scientific field), you need empirical clues - that is, results of experiments that will guide the theorists in which direction they should pursue, because the space of theoretical possibilities (without the limitations that come from experiment) is infinite. The LHC was a major disappointment to many theorists because it confirmed one theory underlying the Standard Model, but gave no further information. While this one theory is very important, very beautiful, and earned Hogia a Nobel Prize, the LHC gave no hint of what physics exists beyond the Standard Model. In other words, we need an experiment that will open a window to things we still don't understand, and that's where the LHC failed (not in the sense that the physicists and engineers who built it and worked on it failed because they did a bad job, but in the sense of failing to deliver results).

  5. Overall, the intention of the title and the article is that the physicists need experimental results, which the current accelerators cannot provide, in order to lead the theories in the right direction. The construction of such a monster is very expensive and the politicians in their extreme severity prefer to direct our money to other places, but without additional accelerators and in particular the linear one, we probably won't be able to break through. Hence the use of the word "rescue".
    What made you so heavy?

  6. Yellow header for a scientific blog. Not suitable both for the science website and certainly not for Scientific American.
    Physics is just a profession, a scientific branch. It will not be refuted because there is nothing to refute. Only physical theories can be disproved.
    The title could have been less bombastic. "The accelerator that can save the standard model (theory)". But even this statement would be inaccurate. An experiment can disprove a theory, but not save it. Maximum - confirm it (support).

  7. Shmulik,

    You weren't wrong at all, that's a pretty good summary of the topic. The circular accelerators produce more radiation (because of the circular acceleration, i.e. the energy required to change the direction of the accelerated particle and not just increase its speed) and therefore can reach the highest energies only when accelerating heavy particles (for which the loss of energy to radiation is less significant). Of course they have the advantage that their effective length is greater because the particle can be accelerated over many revolutions.

  8. I wanted to ask Albentazo why the LHC is circular compared to the linear accelerator that is currently being planned and if there is a possibility that the LHC will use electrons instead of protons. I did a short preliminary search on Google and it turns out that there is bremsstrahlung radiation (with the fancy German name: Bramsterlung) that is emitted when a radiant particle is accelerated. When the particle radiates, it loses speed and must compensate for the loss of speed to the radiation. An electron loses speed much faster than a proton, since it is much lighter than it. An electron will radiate its full speed before completing one revolution. It is possible, and even mandatory, to compensate for the loss of speed in protons, but in electrons the amount of energy required will cost too much money.
    This explains why the electron accelerator will be linear and why there is no point in the LHC firing electrons.
    Albantezo, was I wrong big time? I tried to summarize the attached links.

  9. A. Ben Ner,

    Not all superpartners have a short half-life. In theory, there are also stable supersymmetric particles, such as the Fermionic sibling of the gauge bosons (putinos, gravitinos, etc.).

  10. It is not clear how the supersymmetric particles, whose life time is so short, can constitute the dark mass that astronomers and cosmologists expect to find.

  11. Moshe,

    How do you think this can be done? In the accelerators that we know how to build today, there is a direct relationship between the size (the length of the acceleration path, whether it is the circumference of a circular accelerator or the length of a linear accelerator) and the energy that can be reached, which is the goal of an accelerator: to reach the highest possible energy (in principle, of course, sometimes There are secondary goals such as the amount of radiation that is produced, etc.).

    If you have an idea for an accelerator that reaches high energies, of the order of magnitude currently being studied (ie, order of magnitude of ten tera electron volts and above) and that is small in size, please share this idea with the scientific community. You can take out a patent first and make a lot of money.

  12. I don't understand what the title of the article "The particle accelerator that can save physics" means? Physics is constantly facing the test of refutation. The more appropriate name for the article could be "The particle accelerator that can upgrade physics". This is what will happen if more particles are discovered in the world of particles. There is no rescue here. There is an upgrade here.

  13. I don't really understand why they build the boosters so big. In my opinion, it is possible to reduce them significantly and get no less quality results (and maybe even more).

Leave a Reply

Email will not be published. Required fields are marked *

This site uses Akismat to prevent spam messages. Click here to learn how your response data is processed.