You use words like "squarks" and "neutralinos", which sound very similar to quarks and neutrons. What's the difference, if you don't mind explaining? Also, since I know almost nothing about this, if the dark matter is weakly interacting, shouldn't it pull itself into a really small area eventually? If there isn't a negative repulsion between dark matter components, like there is with electrons and via the weak field, why doesn't it all just collect itself in a giant clump?

[–] Stardust@kbin.social 0 points 1 year ago (1 children)

Neutralinos and squarks are entirely theoretical counterparts as part of an extension to the standard model, which were expected to be observed at the LHC as 'natural' but weren't and we have no concrete reason to think they exist; the Standard Model of normal matter still reigns supreme. However if there are really dark stars it does lend some actual support, and would be the first actual evidence.
Basically the idea is there might be a symmetry between bosons (spin 1) and fermions (spin 1/2), a 'supersymmetry', so that every known (fundamental) particle has a secret doppleganger. I vaguely recall one motivation was providing counter-terms, as if you add more matter it can blow up the Higgs, but the irony is the Higgs is fine if you just... Don't add any dark matter, like the asymptotic safety program pointed out and actually garnered a prediction of the Higgs mass with before anyone measured it. And everyone argued it would be more 'natural' if the new particles showed up at LHC energies. They didn't.
Personally I'm betting against it; supersymmetry has just actively had predictions working against it so far. The particles would end up introducing more parameters than they solve.

[–] SIGSEGV@waveform.social 0 points 1 year ago (1 children)

Thanks. Is "if you add more matter it can blow up the Higgs", because the Higgs only interacts via gravity, or something?

[–] Stardust@kbin.social 1 points 1 year ago

So, the Higgs is, if I recall right, sensitive to the masses of other particles, and I don't think this has much to do with gravity per say (gravity just reacts to mass-energy to curve spacetime) but the fact that Higgs can decay to other particles and also feels the 'Higgs' effect/field of which the Higgs boson is kind of like a left over. The Higgs mass can thus 'blow up' from contributions from other particles, because in a quantum field a particle will potentially fluctuate to several particles and then back again, and of course, you can't decay into something if you are less energetic than it. [edit: although that might not be important, if 'virtual particles' heavier than you vanish before anything can measure them. actually now that I recall I think it was mainly virtual particle contributions that mattered here.]

I very hazily recall that it is possible to have some mass from non-Higgs effect sources, for instance quarks binding to each other contributes most of a proton's mass rather than the Higgs effect, so the Higgs boson could have /some/ mass even if we turned off all the Higgs bits except for the boson itself, but my impression was that it was majority from Higgs interactions, from which the Higgs boson is relatively 'unprotected' from being ballooned up. A counterpart particle can provide counterterms to help keep mass low, like a seesaw, but the standard model Higgs has no such counterpart unless you introduce something extra.