4
$\begingroup$

In Vienna, about one year ago, researchers proposed that a previously-discovered meson is the glueball, a massive particle that consists of massless gluons (this is their published paper in Phys. Rev. Lett). Can't the same mechanism be responsible for the mass of quarks, leptons and other massive particles? If so, they have to be composites of massless particles, of course, so maybe this discovery is at the same time a hint that that's indeed the case (as in the Rishon theory of Harari).

$\endgroup$
1
$\begingroup$

In the case of glueballs the large majority of the mass is not caused by the Higgs mechanism but from the potential energy that binds the gluons together (remember $E = mc^2$). A similar mechanism gives hadrons and mesons (bound states of quarks and gluons) the majority of their mass. See for example this threat.

Quarks and other leptons themselves are (as far as we know) elementary particles. This idea is currently being supported by a large number of scattering experiments, we would therefore not expect their mass to be coming from potential energy as nothing binds them together. There have been many alternative ideas to the Higgs mechanism in the literature, for example, a popular alternative was known as technicolor. This is why the discovery of the Higgs boson in 2010 was such an important step in our understanding of particle physics.

Edit What do you mean with 'Rishon theory'? I had to look it up on Wikipedia and I suppose you are referring to a 'possibly new substructure to matter' as is apparently popularized in the recent Star Trek movies? In that case, I think the answer is (as I mentioned above) that there is currently no reason to believe quarks and leptons are not fundamental.

$\endgroup$
  • $\begingroup$ I haven't seen the film but was already for a long time fan of Harari's theory. With the minimum number of particles (2) you can built up all elementary particles. And remember that in hadrons and mesons the constituent particles carry mass, while gluons do not. And massive glueballs (their velocity is less than the speed of light) are just as Higgs particles predicted by the standard model. For sure in 2012 (not 2010) a new particle was discovered, but this particle decays too fast compared to the calculations. $\endgroup$ – descheleschilder Oct 19 '16 at 13:51
  • $\begingroup$ Even if quarks were massless they would still give rise to massive bound hadron and glueball states. Your hypothesis basically comes down to the question "are leptons fundamental particles?" As I said there is no experiment that indicates this would not be the case (at currently probed energies). You can look for 'deep inelastic scattering'. What am I supposed to make of the sentence "in 2012 a new particle was discovered, but this particle decays too fast compared to the calculations."? $\endgroup$ – JgL Oct 19 '16 at 17:05
  • $\begingroup$ The rishon theory doesn't need Higgs mechanism because the weak force is a residue force in the theory. Compare it with the old strong force:itwas believed to be transmitted between nucleons by the massive pion. Later it was found this is a residue force. There is a formula I once read and wrote down. It comes from calculations in the framework of the Higgs mechanism. It's this one (written a bit cumbersome): Wexp2(1-Wexp2/Zexp2)=(2exp(1/2)@pi)/Gf, where W and Z are the masses of the weak force carriers, @ the fine structure constant and Gf the relative strenght of the weak force. $\endgroup$ – descheleschilder Oct 21 '16 at 15:19
  • $\begingroup$ After some fiddling around with the masses of the pi+ and pi0 I found: $\endgroup$ – descheleschilder Oct 21 '16 at 15:25
  • $\begingroup$ After some fiddling around with the masses of the pi+ (or pi-) I found (1-pi0/pi+)=2exp(1/2)@pi/Gs, wich results in about 0.032, after setting Gs equal to one, wich could be the formula equivalent to the formula in the previous comment, but applied to the old strong force. Another advantage of the rishon theory is that it explains the apparent fact that only normal matter exists, and no anti-matter. According to the theory there are equal amounts of both. Just count the number of rishons and anti-rishons in the electron, the proton, the neutron and the neutrino. $\endgroup$ – descheleschilder Oct 21 '16 at 15:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.