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I am not comparing passive gravitational mass with rest inertial mass. Is there an evidence in Standard Model which says that active gravitational mass is essentially mass assigned by Higgs mechanism.

Earth is a Spoon
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    I've been working on a similar question. Let me refer to this video that started my thinking: http://www.youtube.com/watch?v=9Uh5mTxRQcg, which says "the standard model misses out on gravity". I should qualify that I have no idea what that means, but clearly, the Higgs mechanism accomplishes something along the lines of allowing mass values to exist within QFT, which the theory might have otherwise precluded. Now, exactly how well does the standard model allow for these values to give rise to inertia and spacetime curvature (GR topics)? Good question! – Alan Rominger Jul 05 '12 at 18:29

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The mass of a particle is the energy that it has when it is at rest. The Higgs only makes it that particles oscillate between different helicities, so that you can make them be at rest, and their energy at rest is equal to the rate of oscillation between the two helicities. This energy gravitates like any other energy.

Ron Maimon
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  • Sounds good around Higgs ju-ju, but how is it an answer? – Earth is a Spoon Jul 05 '12 at 19:57
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    @Sachin: please re-read Ron's answer: This energy gravitates like any other energy. – Christoph Jul 05 '12 at 20:10
  • @Christoph I read that. Comparing with a general energy attribute can't be an answer. – Earth is a Spoon Jul 06 '12 at 03:35
  • @SachinShekhar: I am not comapring anything--- the energy of a particle at rest is it's mass. That's what mass means. The Higgs gives a fermionic particle at rest an energy (from helicity swapping) a mass proportional to the coupling to the higgs, or the swapping rate (in amplitude). – Ron Maimon Jul 06 '12 at 04:43
  • Then how does it say that this energy creates quantum of space to cause a spacetime curvature from other similar energy? – Earth is a Spoon Jul 06 '12 at 05:36
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    @SachinShekhar: The gravity is independent of whether it's a Higgs or a gluon making the energy. The Higgs gravitates, the massless things gravitate, and the massive things made from the Higgs plus the massless things also gravitate, all according to the energy and this has nothing to do with producing mass. Gravity is sourced by energy-momentum and stress, not by rest-mass. – Ron Maimon Jul 06 '12 at 07:27
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The standard model itself says nothing about gravity at all, so no.

In any case, the thing that couples to gravity is energy, not just mass. This is different from the mass that the Higgs field gives to particles, which is actually just (rest) mass, and does not count energy.

David Z
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  • The energy you are talking about has to do with passive gravitational mass (in sense of General Theory of Relativity). I am talking about active one. – Earth is a Spoon Jul 05 '12 at 18:47
  • The active one isn't doing work against field to involve with energy.. – Earth is a Spoon Jul 05 '12 at 18:51
  • Curious - if the Higgs mechanism had something to do with active mass (or matter-energy in general), then I would expect photons (among others) to interact with the Higgs field. My guess is that they don't, and I think this graph confirms that: http://en.wikipedia.org/wiki/File:Elementary_particle_interactions.svg – Alan Rominger Jul 05 '12 at 19:05
  • Both kinds of gravitational mass are actually energy. @AlanSE, you're right that photons don't directly interact with the Higgs field, and yet they do couple to gravity, which is one way you can tell that the Higgs is not the sole "producer" of gravitational mass. – David Z Jul 05 '12 at 19:31
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    -1: Come on! This is the second time you encourage the persistent wrong thing that rest mas does not count as energy. Of course it counts as energy! All mass is energy. – Ron Maimon Jul 05 '12 at 19:32
  • @AlanSE Photons don't have active gravitational mass.. – Earth is a Spoon Jul 05 '12 at 19:33
  • @Ron Yes, of course rest mass is energy. When did I ever say it wasn't? – David Z Jul 05 '12 at 19:33
  • @SachinShekhar they do. It's given by the electromagnetic stress-energy tensor. – David Z Jul 05 '12 at 19:35
  • @DavidZaslavsky huh, but if rest mass and other kinds of mass (potential, kinetic, photons, etc) create inertia and interact with spacetime curvature in the same way, it would seem crazy to me that this Higgs field would explain only one type and not have anything to do with the others! It seems like unifying particle physics and gravity would be difficult to do while preserving the concept of the Higgs field as a regular type of field. If the Higgs field had a value, it seems like that should be gravitational potential. But it's not. I don't understand what it is. – Alan Rominger Jul 05 '12 at 19:40
  • @David I thought you're talking about energy aspect of the field. If you're talking about mass-energy equivalence, how is rest mass assigned by Higgs mechanism not energy? – Earth is a Spoon Jul 05 '12 at 19:40
  • @David Electromagnetic stress-energy tensor is unresolved. See: http://en.wikipedia.org/wiki/Abraham%E2%80%93Minkowski_controversy – Earth is a Spoon Jul 05 '12 at 19:47
  • No, that's not what this discussion is about. And if we are to continue this, let's take it to [chat]. – David Z Jul 05 '12 at 20:04
  • @David Fine.. its not about energy aspect of field. Can you explain the last sentence of answer? How is rest mass not energy? – Earth is a Spoon Jul 06 '12 at 03:29
  • Mind it, we have created mass in LHC based on E=mc^2. – Earth is a Spoon Jul 06 '12 at 03:32
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I will answer your deleted question, which is relevant. Read this link to get a framework of where the SM stands.

Look at table 1 and you will see that in the microcosm of quarks and leptons the gravitational interaction is so weak that it is completely irrelevant and certainly its effect on the values used of the standard model cannot be measured with our present experimental accuracies.

You ask:

Is there an evidence in Standard Model which says that active gravitational mass is essentially mass assigned by Higgs mechanism.

The standard model is mainly descriptive, it is a method to mathematically tie together a very large number of experimental data, economically, for the three stronger forces, strong, electromagnetic and weak. Because the strength of the coupling of the gravitational interaction is very much smaller than the coupling of these three forces ( Table 1 in link) there is no measurable predictable effect. In any case, as the quark and lepton masses are parameters in the SM, not predicted values,any tiny effect will be absorbed in the definitions.

The Stndard Model is not a theory of everything, but must be embedded in a theory of everything because it is really a shorthand for all the data we have up to now on quarks and leptons. A theory of everything will of course incorporate the gravitational force, and theorists are working on it, with prime candidate the string theories.

anna v
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