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I What is mass according to the standard model?

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  1. Apr 10, 2017 #1
    All particles get their mass from the higgs field. But how? According to the standard model what is "mass" and how do particles get it?
     
  2. jcsd
  3. Apr 10, 2017 #2

    Nugatory

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  4. Apr 11, 2017 #3
    I fail to see how this is a meaningful "correction" apart from the added precision of specifying fundamental particles. Other than that it's obviously just semantics---in particle physics the words "particle" and "field" are often synonymous. This would be more understandable if the role of the Higgs vev had been explained, but it wasn't. A few sentences later the author adds

    which is clearly nonsense.

    But the Higgs doesn't "resist motion" whatsoever. If it did, it'd violate Lorentz invariance. What's worse, massless particles have some form of inertia too: a photon that impinges on a mirror will transfer about twice its momentum to the mirror, etc.

    First of all, even defining what is meant by the mass of a quark is somewhat ambiguous because free quarks don't exist. It's correct that what is called "current" mass comes from the Higgs mechanism, but the "constituent" mass, which is the mass the quark has in the environment of the nucleon, is often discussed as well. It's not really fruitful to say that constituent mass is about binding energy, as the author implies, because stable objects have a smaller mass than the sum of the mass of the constituents! I understand that chiral symmetry breaking is even harder to explain to laypeople than the Higgs mechanism, but it's best to say something vague e.g. "it comes from the strong interaction" than writing something misleading.

    ??? There's no reason why something that has mass "must" interact with the Higgs field. Dark matter could be in an wholly dark sector, forever undetectable, and strictly speaking we have no right to expect otherwise.

    Another "correction" that doesn't help much. The text below it is a bit better but there's no useful sense in which a particle is "generated" by the field. What is meant by "particle", as always, depends on context, but where applicable we typically mean something like number eigenstates or some related observable of the Higgs field.

    Depending on how precise you want to be, it is largely a matter of taste whether you're willing to call the Higgs field a "medium". However, only science fiction has "energy fields". Physics does not. Energy is just a number that we know doesn't change under the vast majority of physical processes.

    So, in short, I don't think this article is particularly useful at eliminating popular misconceptions about the Higgs mechanism, and in fact it seems to add some new ones.
     
  5. Apr 11, 2017 #4

    mfb

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    Neutrinos could have a different origin of mass. The Higgs boson itself has an important different contribution to its mass.

    The article is not without issues, but I think it is better than what you often see in the news.
     
  6. Apr 11, 2017 #5
    Yes, but the article didn't say that.
     
  7. Apr 11, 2017 #6

    ChrisVer

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    if we want to play with semantics, the Higgs field's vev is responsible for the bare masses of particles (those that appear in the Lagrangian before renormalization)... the mass of a particle is a product of:
    1. its bare mass
    2. its self-interactions.
    right?
     
  8. Apr 11, 2017 #7
    Renormalization adds to a theory essentially whatever terms aren't prohibited by some symmetry. "Pure" quadratic interactions (mass terms) are prohibited by symmetry for most particles in the standard model. Mass terms for gauge bosons are forbidden by gauge invariance, and mass terms for fermions (neutrinos possibly excepted because nobody knows about neutrino masses) are forbidden because the left and right handed components (which get mixed by a mass term) transform according to different representations of the gauge group. There are still radiative corrections to masses though, and they can be calculated with diagrams that include the Higgs.
     
    Last edited: Apr 11, 2017
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