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Physicists Discover A Possible Break In the Standard Model of Physics (futurism.com) 260

Slashdot reader freddienumber13 write: A series of experiments has shown that tau particles have decayed faster than predicted by the standard model. This has been observed at both CERN and SLAC. This suggests that the standard model for particle physics is incomplete and further research is required to understand this new area of physics.
Nature adds: One of the key assumptions of the standard model of particle physics is that the interactions of the charged leptons, namely electrons, muons and taus, differ only because of their different masses... recent studies of B-meson decays involving the higher-mass tau lepton have resulted in observations that challenge lepton universality at the level of four standard deviations. A confirmation of these results would point to new particles or interactions, and could have profound implications for our understanding of particle physics.
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Physicists Discover A Possible Break In the Standard Model of Physics

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  • by Anonymous Coward on Sunday June 18, 2017 @07:39PM (#54644259)

    Is this really so surprising? I know quite a few physicists (and some armchair physicists) who have long believed the standard model to be incomplete. The measurement problem will always have us making theories that are very, very hard to prove correct.

    Additionally (granted, non-scientifically) the standard model 'feels' wrong. The model may explain the behaviors that we see but it seems overly complex for nature. Much like relativity there may be more than meets the eye going on here.

    It has seemed like we were in a bit of a stagnation lately and I'm glad there are some new experimental results making us look at the standard model critically. It's not only good science it's exciting science.

    • by Pseudonym ( 62607 ) on Sunday June 18, 2017 @08:38PM (#54644457)

      Is this really so surprising?

      It's surprising that it took so long to (probably) find an actual experimental break in the standard model.

    • by Anonymous Coward on Sunday June 18, 2017 @09:02PM (#54644531)

      We don't merely think the SM is incomplete, we know for a fact that it is, because it doesn't describe gravity. Just as we know for a fact that GR is incomplete, because it's not a quantum theory at all.

      There's other breaks in the Standard Model which appear to occur at energy levels we might conceivably actually be able to reach (Like this tau decay anomaly, and time-reversal invariance breaking in... D or B meson), and the long known problem of unitarity violation in the electroweak force above about 2TeV (Above this energy, known electroweak interactions have a probability exceeding 1, so something we don't know about has to be "fixing" this). And the classic hierarchy problem: The correction terms we know should give the Top an enormous mass if the coefficient on those term is near to 1, so something must be cancelling these (if one doesn't believe that the coefficient on the corrections is absurdly, vanishingly small).

      There is also the grand unified theory scale around 1e19 GeV, where the strong and electroweak forces will merge into one and nobody knows how that'll work, but the energy level is so high it will never be examined directly.

      So it's not surprising. It's cool!

    • by Roger W Moore ( 538166 ) on Monday June 19, 2017 @01:48AM (#54645435) Journal

      Is this really so surprising? I know quite a few physicists (and some armchair physicists) who have long believed the standard model to be incomplete.

      We know for certain that the Standard Model is incomplete because it cannot explain gravity. It it also missing Dark Matter and a large enough asymmetry between matter and anti-matter to explain the universe being full of matter. However, none of these explains why this result is not surprising.

      The reason that this result is not surprising is because of the number of Standard Model measurements which experiments like LHCb, Babar and Belle make. There are literally thousands of ways in which these experiments have tested the Standard Model and when you make 1000 measurements finding one that over 3 sigma from expectations is not at all unsurprising - in fact you would expect 3.

      Now 4 sigma is better because only about 1 in 15,000 measurements will, on average, be this far apart if the Standard Model applies. However, here they have combined multiple experiments but without the respective collaborations being involved. This means it is highly possible that they have failed to combined systematic errors correctly because they are restricted to using only published data. Most combined results come from working groups involving all the collaborations involved e.g. ATLAS+CMS combined results at the LHC, D0+CDF combined results from the Tevatron etc. which can redo parts of the analysis to combine errors properly.

      So while it is possible they may be on to something it is far from certain and this is hardly a major result that will elicit much excitement. This is probably why it was published in Nature! While I know this is an important journal for many fields, for particle physics it is largely irrelevant. All the important results in the field are published in journals like Phys Lett B, PRL, Phys Rev D, JHEP etc.

    • by GNious ( 953874 )

      Is this really so surprising? I know quite a few physicists (and some armchair physicists) who have long believed the standard model to be incomplete.

      If you know any that thinks otherwise, don't consult them for anything related to physics.

    • by gweihir ( 88907 )

      Well, I agree that the standard model feels more than a bit like a trained classificator after overfitting, i.e. it matches all reliable observations (except this new one), but it does not seem to capture a clean, simple and elegant underlying model. In laymen's terms, it is a bit like describing each field of a chess-board by its color, and neighbors, sometimes even with various pieces on it or next to it, instead of saying "8x8, alternate black and white". A reason is that a "clean, simple and elegant" mo

    • by epine ( 68316 )

      The model may explain the behaviors that we see but it seems overly complex for nature.

      Please reformulate that statement as a viable Bayesian prior.

      Inquiring minds want to know.

      For extra points, precisely where does this "seems" originate, and, most crucially, does it resemble a starfish?

  • Hmmm, that's odd. Whiskey Tango Foxtrot, what's happening here?
  • tau particles have decayed faster than predicted by the standard model

    Caused by Dark Time.

  • Does this impact the accuracy of the dating of the current dating methods such as radio carbon, caesium etc?

  • by jandersen ( 462034 ) on Monday June 19, 2017 @04:25AM (#54645795)

    We have known for a long time that the standard model isn't complete, not least since it does not incorporate gravity in any way. I think most physicists are surprised at how QM still seems to hold together - unlike GR, it is a really complicated theory, mathematically; it is all too often not well understood by the experimental physicists, and there are examples of techniques (like quantization) being applied as a set of rules thumb, a bit like 'first we caluculate the Hamiltonian for a classical system, then use the magical quantization rules'. Amazingly, it often works even if it is mathematically incorrect, but it is of course not going to last, I think; there must be cases where the cracks in the reasoning have been plastered over by the statistical noise in the measurements, and once we see clear evidence that the theory doesn't hold, we will have to go back over old data and discover the cracks we didn't spot back then.

    This discrepancy in the decay of the tau lepton is probably one of these cracks, and I think it is quite exciting, but it isn't quite the sensation the editors want to make of it. I have already read about it several times, even on Scientific American and ScienceDaily, and I have heard it mentioned in recent BBC podcasts; Slashdot's editors would do well to stop reading the big-eyed, gawping articles in glossy magazines like futurism.com, and instead reading the slightly more sober stuff in news closer to the source. You guys should stop perpetuating the ideaa that science is some sort of cool entertainment and scientists are some sort of attention seeking rock-stars.

  • by dhaen ( 892570 )
    Who want's to bet it'll be another one of those faulty cables?
  • the way the universe actually works is not a constant.

Get hold of portable property. -- Charles Dickens, "Great Expectations"

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