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Science

Scientists At Fermilab Close In On Fifth Force of Nature (bbc.com) 84

Posted by BeauHD from the theoretical-showdown dept.
An anonymous reader quotes a report from the BBC: Scientists near Chicago say they may be getting closer to discovering the existence of a new force of nature. They have found more evidence that sub-atomic particles, called muons, are not behaving in the way predicted by the current theory of sub-atomic physics. Scientists believe that an unknown force could be acting on the muons. More data will be needed to confirm these results, but if they are verified, it could mark the beginning of a revolution in physics.

All of the forces we experience every day can be reduced to just four categories: gravity, electromagnetism, the strong force and the weak force. These four fundamental forces govern how all the objects and particles in the Universe interact with each other. The findings have been made at a US particle accelerator facility called Fermilab. They build on results announced in 2021 in which the Fermilab team first suggested the possibility of a fifth force of nature. Since then, the research team has gathered more data and reduced the uncertainty of their measurements by a factor of two, according to Dr Brendan Casey, a senior scientist at Fermilab. "We're really probing new territory. We're determining the (measurements) at a better precision than it has ever been seen before."

In an experiment with the catchy name 'g minus two (g-2)' the researchers accelerate the sub-atomic particles called muons around a 50-foot-diameter ring, where they are circulated about 1,000 times at nearly the speed of light. The researchers found that they might be behaving in a way that can't be explained by the current theory, which is called the Standard Model, because of the influence of a new force of nature. Although the evidence is strong, the Fermilab team hasn't yet got conclusive proof. They had hoped to have it by now, but uncertainties in what the standard model says the amount of wobbling in muons should be, has increased, because of developments in theoretical physics. In essence, the goal posts have been moved for the experimental physicists. The researchers believe that they will have the data they need, and that the theoretical uncertainty will have narrowed in two years' time sufficiently for them to get their goal. That said, a rival team at Europe's Large Hadron Collider (LHC) are hoping to get there first. The results have been announced to the public and submitted to the Journal Physical Review Letters.
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Scientists At Fermilab Close In On Fifth Force of Nature More

Scientists At Fermilab Close In On Fifth Force of Nature

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  • Does it have to be said? (Score:5, Funny)

    by ciurana ( 2603 ) on Thursday August 10, 2023 @10:54PM (#63757998) Homepage Journal

    Multipass!

  • I remember seeing an interview where someone had claimed exactly this regarding the UAPs. That Einstein got it wrong and there was a fifth force

    • Re:The alien interviews were right (Score:4, Funny)

      by DamnOregonian ( 963763 ) on Thursday August 10, 2023 @11:05PM (#63758010)
      Yes. Brawndo does in fact have what plants crave.

      • Re: (Score:2)

        by dddux ( 3656447 )

        You're joking but you don't understand how important electrolytes are for plants, and Brawndo contains a lot of electrolytes. It says on the tin.

    • Re:The alien interviews were right (Score:5, Interesting)

      by sg_oneill ( 159032 ) on Thursday August 10, 2023 @11:44PM (#63758050)

      9 times out of 10 when someone invokes the big name in a hetrodox claim about physics, they usually are speaking out their arse.

      Einstein had nothing to say about the strong or weak nuclear force, cos they hadn't been discovered yet. The strong and weak nuclear forces are both under 50 years old.

      So Einstein wasn't "Wrong", he never even discussed the topic, because the topic hadnt been discovered yet.

      • Not to mention that Einstein's own work on one of the things generally called "forces", was demonstrating that it was in fact, not a force.

        OP is regurgitating shit he heard on Joe Rogan podcasts.
        • Joe Rogan podcast, for people inquisitive enough to listen to Joe Rogan but not enough to read an actual book or even a long form article.

      • Interactions pre-date Standard Model (Score:5, Informative)

        by Roger W Moore ( 538166 ) on Friday August 11, 2023 @06:00AM (#63758412) Journal

        Einstein had nothing to say about the strong or weak nuclear force, cos they hadn't been discovered yet. The strong and weak nuclear forces are both under 50 years old.

        No, the Standard Model is just under 50 years old but the knowledge of the forces predates the SM by quite a bit. The weak interaction dates back to 1933 with Fermi's 4-fermion vertex and electroweak unification - as included in the SM - was proposed in the 1960s with W and Z bosons.

        Similarly, the first model for strong interactions, Yukawa's meson theory, dates back to 1935 and, like Fermi's weak interaction theory, is a low-energy effective theory. Gell-Mann's quark model was proposed in 1964 and the full development of colour charges and gluons in 1973.

        So Einstein, who died in 1955, definitely knew of the early models for both strong and weak interactions.

        • Re: (Score:2)

          by ceoyoyo ( 59147 )

          True, but general realtivity was published in 1915, so Einstein did most of the work he's known for when the only known forces were gravity and electromagnetism.

        • From Wikipedia [wikipedia.org] (emphasis mine):

          a particularly conspicuous blemish of [Einstein's] model was that it did not accommodate the strong and weak nuclear forces, neither of which was well understood until many years after his death.

          Sure they were introduced, but you're thinking of the concepts as they exist today, not as they existed in their infancy. Just because a concept dates back that far doesn't mean that it was well understood, widely circulated, or even as correct as it subsequently became.

          • No, if you read my post you'll note I specifically refer to Yukawa's meson model and Fermi's 4-fermion interaction which were precisely the models of the strong and weak interactions known during Einstein's lifetime. The comment was in response to a claim that Einstein had nothing to say on the strong and weak interactions because they were not known in his time - the facts are that they were known and he could have commented on them.

            Indeed, his special relativity and contributions to quantum mechanics m

      • The strong and weak nuclear forces are both under 50 years old.

        Wow. How did the universe survive so long without them?

    • Wake me up when they discover how to activate a wormhole/blackhole/whitehole, open a door to another dimension (for something to come through to our side, of course), or travel somewhere far through hyperspace.
      Until then it's just arguing about the last page of the physics book should say.
       

    • I met some passing extraterrestrials and they said they only want to mutilate cows and molest the humans. The made up attention around military activity puts them in a bad light, although it is a useful coincidental distraction. They do not want to wage a war, but they were promised a fun holiday on earth by the trip organizer. This fifth force thing is way over their so called heads.

    • When did Einstein say there is no fifth force? That sounds like a pretty bold statement even for a scientist trying to unify the forces.

    • There are 6 fundamental forces.

      Fuzzy haired crackpot scientist pulled things out of his ass -- cosmological constant and speed of light is constant. At least he was smart enough to recognize his own Theory of Relativity was incorrect: [youtube.com]

      "Classical mechanics, as well as the theory of relativity in the narrower sense, which has been discussed briefly in the foregoing, suffer from an undeniable fundamental defect that is accessible to epistemological arguments." -- Einstein

    • That's the Gravity 1 and Gravity 2 claim.

      Some current MOND models say something similar though sci-fi knew at the time that Einsteinian gravity didn't work at the subatomic model.

      Although there are now relativistic proton models that bridge /that/ gap.

      We might wind up qualifying each at the engineering level before solving it mathematically.

      Of course the mental defects on here will vociferously insist that what they learned in high school explains all observations, so be careful not to get any stupid on you

  • We are vulnerable to the ones that have admin access, but access has been leaked and can be stolen or even hacked.

  • This just might invalidate all of quantum theory.

    • Re:I'm ready to toss quantum theory out the window (Score:5, Informative)

      by slack_justyb ( 862874 ) on Friday August 11, 2023 @01:10AM (#63758118)

      What?

      The anomalous magnetic moment of the muon was calculated at 0.0011659180, that is the standard g-factor of 2 minus the summation of exchange of "infinite" virtual particles. However, the muon is more massive than the electron and so virtual interaction increases as a square to quantum mass. So using the muon's dipole moment to probe for another interaction was always something of interest. The fact that the g-2 is ever so slightly off from the calculated anomalous magnetic moment points to some additional interaction that's not being calculated.

      QED, indicates that the magnetic moment of 1/2-spin particles is given by the Dirac equation. u=g(e/2m)S. It different than classical dipole moments because quantum spin plays a major role in the alignment of a particle with an external field. But that g is the g-factor that we're speaking of, and that g-factor is something we can calculate, but doesn't mean we'll always have it EXACTLY correct. Say when an electron deflects, if it does so via the exchange of just a virtual photon, then the g-factor is 2. But Feynman indicates that more than one interaction with a virtual particle can occur. The electron could exchange two virtual photons, or one virtual photon could become a virtual positron/electron pair cancel each other out and return to being a virtual photon. Every interaction adds just a little bit more to that g-factor. Eventually, the amount that's added between the 100th and 101st interaction is so small it's outside consideration. We've been able to do calculations of trillions upon trillions of interactions on supercomputers to get the calculate g-factor to twelve digits.

      But that's the thing, our calculated g-factor requires us to be able to toss in every single possible virtual exchange that could happen. A virtual gluon exchange, a virtual Higgs exchange, etc.. So if we're missing a fundamental force, then that force isn't in any of our calculations and so the g-factor is going to be off. The standard model predicts this. And so, the Fermilab experiment shows, yeah the anomalous magnetic moment is off a bit. The anomalous magnetic moment is the difference between the g=2 from a single interaction and the g-factor from hundreds of summed up interactions. Basically the anomalous magnetic moment gives us the domain of error on (u) from the Dirac equation that can happen from random quantum virtual interactions. So the calculated anomalous magnetic moment and the observed anomalous magnetic moment are different enough that it warrants deeper study.

      Now we don't see this in the electron because the electron is quite light. So the number of interactions with virtual particles is going to be less than the muon. And the tau is likely to interact even MORE with virtual particles than the electron and the muon. But here's the thing. All of this will just point in a direction. If Fermilab hits five sigma, it'll still need to be independently confirmed, which will take a while, and even after that if that's all good. What all this means is that there is some additional force whose virtual particle interacts very, very weakly. It doesn't tell us the whole story, but it will indicate a direction to go in which is better than where we are currently are.

      But QED has always indicated that the g-factor can only be correctly calculated if we know all forces and can calculate an infinite number of interactions. So we'll always be a bit off if we used ONLY this method in the search for particles. Lucky us, we have many different methods. But this one is a useful one for the muon and the tau (which we haven't gotten around to dealing with as taus are really tricky), but there's only going to be so far we can use this method and this method doesn't pinpoint anything, just tells us that "something else" is interacting. There is a finite amount of interactions we can sum up in a super computer, so eventually we'll not be able to really do much more with this method once we hit that point. But this far from invalidates anything in QED. QED predicts this.

      • Re: I'm ready to toss quantum theory out the windo (Score:5, Informative)

        by felixrising ( 1135205 ) on Friday August 11, 2023 @03:14AM (#63758236)
        Your summary and interpretation of the muon's anomalous magnetic moment, the g-2 experiments, and the significance of the results is quite thorough and accurate. The ongoing experiments, particularly at Fermilab, have generated a lot of interest in the physics community, primarily because of the implications of the results. If the discrepancy between the calculated and measured values continues to grow or is confirmed, it may point towards new physics beyond the current understanding provided by the Standard Model of particle physics. To reiterate a few key points you made: 1. **Muon vs Electron**: Due to the muon's larger mass compared to the electron, it is much more sensitive to possible new particles or interactions. This makes the muon a useful probe for new physics, even though we still rely on the electron for precision QED tests. 2. **Virtual Particles**: Quantum field theory predicts that particles can interact with each other by exchanging virtual particles. These interactions cause small corrections to the g-factor. For the electron, the leading correction (from photon exchange) gives the famous result \( g = 2 \), but the interactions involving higher numbers of virtual particles give increasingly smaller corrections. 3. **Beyond the Standard Model**: If there's an unknown particle or force not included in the Standard Model, it could show up as a discrepancy between the predicted and observed anomalous magnetic moments of the muon. 4. **The Significance of Five Sigma**: In particle physics, a five sigma significance is a general threshold for claiming a discovery. If Fermilab achieves this with the g-2 experiment, it'll be a strong indication of new physics, but as you correctly pointed out, independent verification would still be essential. 5. **Limitations of the Method**: Indeed, there's a practical limit to how precisely we can compute the g-factor using current techniques and technology. The increasing complexity of higher-order corrections becomes computationally challenging, even for powerful supercomputers. However, it's essential to remember that the anomalous magnetic moment of the muon is just one of many avenues through which physicists are searching for evidence of new physics beyond the Standard Model. If there is a genuine discrepancy between theory and experiment, combining the results from different experimental approaches will be crucial in determining the nature of the new physics.

      • If Fermilab hits five sigma...

        According to Wikipedia, Fermilab already hit 5.1 sigma with respect to the standard model prediction, but there's a catch. The prediction from lattice QCD theory is only 1 sigma away from Fermilag's measurement. So I would say that talk of new physics and particularly some fifth force is wildly premature.

    • This just might invalidate all of quantum theory.

      You might want to learn about Occam's Razor which, loosely put, is that the simplest explanation is usually the best. So while it could be that this is the thread that unravels Quantum Field Theory and gives us a better, more fundamental understanding of the universe there is a much, much simpler explanation that, coincidentally has also been the explanation of every previous similar announcement of a discrepancy between theory and experiment by g-2.

      That explanation is simply that either the theorists

  • beware the hadronic blob (Score:3)

    by at10u8 ( 179705 ) on Thursday August 10, 2023 @11:37PM (#63758042)
    Quantum Chromodynamics is hard
    -- Barbie
    https://www.bnl.gov/newsroom/news.php?a=217530

  • I call it "The Schwartz" (Score:4, Funny)

    by dgatwood ( 11270 ) on Friday August 11, 2023 @03:57AM (#63758286) Homepage Journal

    [Everyone gasps.]

    All (together): The Schwartz!

  • There is a revolution in domain x every week but I see no change. Strange.

  • You experience the forces of gravity and electromagnetism everyday. The nuclear forces act over a much shorter range. If you experience the strong or weak nuclear force in your everyday life, that life isn't going to last many more days.

    • Re: (Score:2)

      by habig ( 12787 )

      If you weren't experiencing the strong force, the hadrons that you're made up of would disappate quite spectacularly and quite rapidly.

      The weak force is harder to "experience", but I assure you that you've got weak force mediated beta decays popping off inside you are quite the impressive rate. Just because you aren't waving a Geiger counter around at the moment doesn't mean it's not happening.

      Have another banana while you're headed over to the shelf to grab the Geiger counter.

      • The strong force affects the nucleus of the atoms that make you up. It doesn't affect you. Any meaningful definition of "you" is as a macroscopic system, not a mass of constituent particles. It's a fine philosophical distinction, but a distinction none the less.

        The weak nuclear force is what allows nuclear decay to happen. But you don't interact with it. You interact with the electromagnetic forces generated by nuclear decay. Again, a fine distinction, but a true one nonetheless.

        • The strong force affects the nucleus of the atoms that make you up. It doesn't affect you.

          By the same argument, gravity only affects the mass of your atoms, it doesn't affect you.

          • You, as a macroscopic object have a mass field which can interact with any other gravity field.

            • No, let's use your bullshit argument again. Only the mass of your atoms interact with any other mass. That other mass doesn't experience your gravitation, only the gravitation of your atoms. Like I said, bullshit, but I guess if you're that dumb you will find a way to explain it away.

  • They have to generate hoopla to keep funding coming. Which is a shame, for there probably are lots of far more promising physics projects that could use those funds.

    • Re: (Score:2)

      by gtall ( 79522 )

      So the folks at Fermi Lab decided to take a crap shoot on muons because of funding? Prior research indicating there was an issue here has nothing to do with it?

      "They have found more evidence that sub-atomic particles, called muons, are not behaving in the way predicted by the current theory of sub-atomic physics. "

      "They build on results announced in 2021 in which the Fermilab team first suggested the possibility of a fifth force of nature. Since then, the research team has gathered more data and reduced the

      • It is possible they found in hole in the method of applying the standard model theory rather than a hole in the theory itself, not a sensational result like new physics but worthy nonetheless.

    • No, what is a shame is there is not enough to amply fund all the projects.
      This is 'wasteful space spending meme' but gets the same point across: https://www.genolve.com/design... [genolve.com]

  • Scientists at Fermilab Close in on Sixth Fundamental Force. /s

    • Re: (Score:2)

      by HiThere ( 15173 )

      That's only if this one proves correct. And it also depends on how people at large think about the extant ones. E.g. if you think about the electro-weak force rather than about the electro-magnetic and the weak forces, then there are only 3 recognized forces. And the strong force has also been unified, though I don't know if that unification has a common name, so there could only be 2 recognized forces. i.e. that and gravity.

  • For me info, please rewatch that Star Trek documentary... Or is it start wars? I think it's the one with the world renown financier Jar Jar Banks

  • Scientists near Chicago say... that's how every joke starts.

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