2
$\begingroup$

I'm interested if any of the particles in the standard model could be potential candidates for dark matter?

I know that we do not see dark matter, therefore dark matter does not interact electromagnetically, therefore charged leptons and photon cannot be dark matter particles.

Dark matter is also stable, therefore we can reject W,Z,H.

But what about neutrinos, quarks and gluon?

$\endgroup$
  • 1
    $\begingroup$ Neutrinos have been considered, but simulations seem to rule out this possibility. And quarks and gluons don't exist outside hadrons, of which the longer living ones proton and neutron, and their anti-particles, interact electromagnetically. Precisely dark matter has been termed as such because no known matter behaves in such a way. $\endgroup$ – rmhleo Aug 15 '15 at 19:36
3
$\begingroup$

For a real answer, each particle would have to be discussed individually and that might get long.

Dark matter possibly being Neutrinos has certainly been proposed and in many ways, Neutrino's lack of interaction makes them a good candidate, as they are essentially "dark" - though "invisible" is perhaps a more accurate term and Neutrinos fly through stuff and don't clump, but it's thought that most dark matter isn't Neutrinos because of temperature, explained in much more detail here.

Single quarks aren't stable, you need 3 quarks for a baryon, 2 for a meson see here the problem with quarks being dark matter is that we've studied quarks extensively and we have a pretty good idea how they behave, preferring to settle into protons at standard space temperatures or proton/neutron combinations and we have a pretty good idea that dark matter isn't just hydrogen. So, as far as baryons being dark matter, (since mesons aren't stable) that's probably unlikely. Bit more on that here.

Gluons, curiously, make up a lot of the mass of a proton and neutron, so they make up a lot of the mass that we experience, but Gluons interact between quarks, so individual "free" gluons seems unlikely.

I think, until Dark matter is discovered, it's impossible to answer this 100%, but I (think), dark matter is probably outside the standard model, though perhaps somebody smarter than me would like to have a go at this question.

$\endgroup$
  • 2
    $\begingroup$ 'but Gluons interact between quarks, so individual "free" gluons seems unlikely.' QCD as we know and love it admits glueballs. But the properties that the theory ascribes to them don't agree with the known properties of dark matter. $\endgroup$ – dmckee Aug 15 '15 at 19:58
  • $\begingroup$ Thank you sir. I had to look up glueballs. Learned something new. :-) $\endgroup$ – userLTK Aug 15 '15 at 22:05
1
$\begingroup$

Quarks are unstable out of hadrons. Gluons transmit the strong interaction between quarks so without quarks there are no gluons. As for neutrino's computer simulations of the early universe show that dark matter was slow while neutrino's are extremely fast (almost light speed). So, you will ask what's dark matter maid from? Supersymmetry could be the answer (in this theory each boson has a fermion as superpartner and vice-versa).In supersymmetry the supperpartners of the photon,gluon,W-boson and Z-boson are the neutralinos (a bit photino a bit gluino a bit wino and a bit zino). The lightest of the neutralino's is stable so dark matter could be made of the lightest neutralino. Conclusion: Dark matter is not made of any particles from the standard model.

$\endgroup$

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.