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Do we have any more power?

Physicists from Tel Aviv University are participating in an experiment launched this week in search of evidence of the existence of a fifth force in nature.

The Jefferson Accelerator Facility in Virginia
The Jefferson Accelerator Facility in Virginia
One of the great achievements of physics in the last 50 years is the ability to attribute all natural phenomena as the result of only four basic forces. The action of these forces is described by models which together received the name "the standard model". When a force acts between one particle and another, its action is transferred between them by a "force carrier". Each of the four forces has its own power carriers. The best known of them is the photon, a particle of light, which carries the electric force. The properties of the subject of the power affect the properties of the power. The photon, for example, is massless and moves without interruption for long distances, thus giving the electric force a long operating range.

Much research effort is focused on the search for phenomena that are "beyond the standard model", that is, not described by the forces we are familiar with. One such attempt was launched this week at the Jefferson Laboratory in Virginia, USA. The name of the experiment is "A Prime EXPeriment" and its purpose is to look for evidence of the existence of a fifth force in nature, and with it a new force. This force subject, which has not yet been discovered, already has a name - it is called "A-frame" and its properties are very similar to those of the photon with a small difference: the A-frame will have a small mass while the photon has no mass at all. If such a force exists, its magnitude will be very low and therefore it is difficult to discover it experimentally, and indeed it has not been observed to date.

In the Jefferson Laboratory, an electron accelerator operates which produces a beam of high-energy electrons. In the experiment, a target made of thin tungsten wires is placed in the path of the electrons. The laboratory's instruments aim to detect events in which an electron hits the target and as a result of the impact an A-prime is emitted which immediately turns into a pair of an electron and a positron.

The experimental nuclear physics research group of Tel Aviv University, led by Prof. Eli Pisetsky, participates in the experiment. Yishai Pomeranz, a doctoral student in the group explains: "If such an A-frame does exist, the chance of it forming and becoming an electron-positron pair is very small, therefore the success of the experiment lies in the ability to bombard the target with a high rate of electrons. On the other hand, pairs of electrons and positrons are easily created as a result of other processes, and it is important that the measuring devices be able to identify in real time the pairs inevitably created by an A-frame, among the tens of thousands of particles that pass through the detectors every second." The team from Tel Aviv University is responsible for calibrating the detectors that identify which type of particle passes through the detector.

The experiment finished its first part this week, where the programming of the devices' capabilities to perform the measurement with the required accuracy was demonstrated. In the next step, a measurement will be made over a month and then the data will be analyzed, then the scientists will be able to say with great precision whether they have found evidence of the existence of a fifth force in nature.

17 תגובות

  1. deer

    Today I tried to find out more about the theory behind the experiment in Jefferson's laboratory, but I did not succeed. In addition, I was probably wrong and misled you in my previous answer, the simple extensions of the standard model are not obtained from adding U1 symmetry to the model, but from assuming an additional SU2 symmetry or several additional SU2 symmetries. Breaking of one of the SU2 bunches at the scale of TeV gives a W-prime particle and an additional Z-prime particle where the Z-particle is the massive photon. You can read more about this in the entry corresponding to W' and Z' bosons in Wikipedia. I apologize for the partial information.

  2. deer

    I think that basically the claim is trivial, that is, any extension of the standard model
    will be accompanied by an additional force corresponding to the additional symmetry. One of the simplest extensions is
    Add another U1 symmetry to the theory.

    Specifically for the experiment at the Jefferson Lab I will try to find out more tomorrow and get back to you.

  3. sympathetic,

    Do you know more details about this fifth force and the reasons for assuming its existence?

  4. Explanation regarding the identification of the particle that created the electron-positron pair:

    The pair is detected by two spectrometers with high precision in measuring the momentum and angle of the particles that pass through them.
    From the measurement of the momentum and angle of the pair, the momentum and energy of the particle that created them can be recovered by conservation of energy and conservation of momentum.
    In the event that a photon created them, the energy would be equal to the momentum since the photon has no mass. If, on the other hand, there is a small difference between the energy and the momentum of the particle that created them, the difference is the mass of that A frame.

  5. sympathetic,

    An interesting explanation, but it seems to me that these things are already known to Avner.

    Good luck

  6. A. Ben Ner

    At the beginning, a little technical explanation with you, sorry:
    Forces in nature are defined by the calibration particles, the particles that transfer the force between two particles. Forces are also determined from the symmetries of the theory. The requirement that a certain symmetry is local gives calibration freedom. The calibration field is the subject of interaction. In the case before us, another symmetry is defined for the U1 calibration symmetry theory, the same symmetry as the photon, but the particle carrying it is massive and therefore not equivalent to a photon.

    In the bottom line, the assumption that there is another massive A-prime particle defines another local symmetry of the theory, therefore it is a new force. It is not enough that the particle is familiar to familiar particles to say that we have the same powers.

    I'll give you an example (which isn't that good but might help my lame explanation). An excited atom can undergo beta decay, a process involving the weak force. The positron emitted from the nucleus can annihilate with an electron that returns to the electronic levels and at the end of the process a pair of photons is obtained. You could argue that the weak force is just an extension of the electromagnetic force, but that is not the case.

  7. The question I ask is, is it justified to call the A-prime a "fifth power".
    After all, the electron-positron pair created by the A-prime decay performs annihilation
    Electron-positron at the end of which all their mass energy becomes photons.
    For this "light" (literally), it is perhaps more correct to describe the A-prime as a part or as a phase
    The advance, the initial force of the A.M. It is also possible that this is the reason for his name, namely:
    (the preliminary stage of the AM power) = (A-prime)
    And all this without underestimating the importance of theory and discovery (if and when..)

  8. It seems like another piece of the puzzle of what is missing today to balance the great equation of the universe, whether it is as dark matter or dark energy or a fifth force.

    I understand that this is due to creative attempts,
    So good luck to everyone 😉

    And thank you Zvi for the answers....

  9. I was wrong in saying that the power is expected to work in short ranges only.
    It seems to depend on the theory.

    It seems to me that for the particle the article is about I was actually right, since it is a massive particle and therefore its range of action is limited

  10. age,

    Your question is very justified and in fact I feel that the article misses the point in that it does not at all explain the motivation for his search for additional power.

    There are theories (such as the well-known Klotza Klein theory) that predict the existence of an additional force of a strength similar to that of gravity, but unlike it, it is expected to act only over very short distances. The Wikipedia entry is not organized enough and it seems that I will have to read a little more in order to understand - I promise to share the understandings I acquire.


  11. to Mr. anti-crank

    Why do you think your opinion will make me decide whether or not to comment on articles?
    If you have a problem with my opinion then save your time and don't read it.
    to Gil Dotan
    It was really important to explain why we need the aforementioned particle and what function it is supposed to fulfill.
    Good Day
    Sabdarmish Yehuda

  12. Mr. Sabdarmish, why does your skepticism or lack of skepticism have any relevance to the news? Who cares what you think about things that are completely beyond your reach?

  13. What math is behind this?

    How did they come to the conclusion that there might be such a power? Are there any equations that confirm this?

    I mean, I understand the desire to think not only in terms of a standard model,
    These are out of the box…. That's the only way to progress, but where did you get the aforementioned particle?

  14. Dear Mr. Sabdarmish, Hello
    I think that in this case, in contrast to the dark mass case, here actually chances are not such a bad result because following the first experiment it is possible to plan future experiments with a longer time, etc. in which they will increase the probability of the target results and perhaps be able to differentiate them from the background results. One month may not be enough - the electrons may need to be run for two years to get a significantly different result from the background conditions. In the matter of dark mass it is perhaps more complicated

  15. How will ordinary positron-electron pairs be distinguished from that of A prime?, by chance?
    Soon news will be published that an A prime particle will be discovered with an 80% chance which is even more than the 75% chance of the dark mass particle!
    I'm skeptical.
    Good night
    Sabdarmish Yehuda.

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