Wednesday, October 4, 2017
A Quark Mass Quote
"In the case of the top quark, we could well say it's simple, but we would be lying to ourselves - how can a particle we consider point-like weigh as much as a full tungsten atom ? We have not understood that yet, and we are indeed far from giving even a tentative answer to this riddle. In fact, the six quarks we have discovered, which make up nuclear matter, have so varied masses (the heaviest one, top, being approximately 60,000 times heavier than the lightest one, up) that one wonders what mass really is.
Is mass of matter corpuscles caused by inertia in the Higgs field or by binding energy of constituents? In the first case we have a down-to-earth "guessplanation" of the phenomenon: as quarks move about in the Higgs field, the heavier of them are slowed down more by a more intense interaction with the Higgs field. Of course note that this explanation, which we know is correct but might not be the full story, is only moving the problem to another department rather than solving it, for the different interactions of the Higgs boson with matter particles are still unknown and free parameters in our model, just as masses are.
In the second case, as Jorge Cham and Daniel
Whiteson would put it (see the cover of their aptly named book, right), we have no idea. If quarks are composite objects, then we know what can cause their mass to be large of small - pretty much the same thing happens with the proton itself, which has a mass much larger than the sum of its constituents, as most of it is due to its internal dynamics. Yet we have no idea of what quarks may be composed of, so we are clueless anyway."
From Tomasso Dorigo's Quantum Diaries Survivor Blog (September 22, 2017).