But even if low energy SUSY is ruled out, isn't it possible that supersymmetric particles would exist but at much higher energies than the LHC can reach, and if so couldn't such particles still fill the role of WIMPs in dark matter theories? That's what I was saying about the landscape model in string theory, I thought that at least some advocates of the landscape believed in supersymmetry but saw no particular reason to believe it would be a low-energy version that would solve the hierarchy problem. For example, when I was looking for info on this I found this quote from p. 259 of the book Naturalness, String Landscape and Multiverse:
"We should emphasise, however, that low-scale SUSY is certainly not a prediction of string theory. 10d stringy SUSY may be broken directly in the compactification process (e.g. through a non- Calabi–Yau compactification) or at any energy scale between KK-scale and weak scale." On Sun, Oct 31, 2021 at 9:06 AM Lawrence Crowell < [email protected]> wrote: > The whole low energy SUSY theory appears to be in trouble. The breaking of > SUSY as the TeV scale appears not to work. This eliminates the neutralino, > which is a condensate of supersymmetric partners of the Z particle and > photon, appears to not exist. This does remove to a fair degree a SUSY > predicted WIMP particle, the neutralino. > > LC > > On Friday, October 29, 2021 at 10:20:20 AM UTC-5 jessem wrote: > >> When you say "WIMPs are most likely ruled out" is that related to failure >> to find supersymmetric particles at LHC? (Correct me if I'm wrong, but my >> understanding was that many physicists hoped supersymmetry would solve the >> 'naturalness problem' of the weak energy scale in a way that required >> supersymmetric particles to have masses in that range, but advocates of the >> landscape model like Susskind thought there needn't be any 'explanation' >> for the energy scales of different forces beyond the anthropic principle.) >> Or are there other reasons to rule them out, like cosmological simulations >> based on WIMPs being unable to match certain cosmological observations >> about the real universe? >> >> Jesse >> >> On Fri, Oct 29, 2021 at 7:15 AM Lawrence Crowell < >> [email protected]> wrote: >> >>> On Thursday, October 28, 2021 at 9:08:55 PM UTC-5 [email protected] >>> wrote: >>> >>>> Lawrence, any guesses as to what Dark Matter could be? Nobody can >>>> find any evidence of WIMPS and now sterile neutrinos seems to have bit >>>> the dust. Would you bet your money on Axions, or some modification of >>>> General Relativity (teleparallel gravity perhaps) or none of the above? >>>> >>>> John K Clark >>>> >>>> ========== >>>> >>>> >>>> >>> I have no commitment to any particular theory. Dark matter might turn >>> out to be some new physics involving mass-energy in an entirely different >>> form from what we traditionally know as particles or fields. Dark energy is >>> most likely some sort of vacuum energy, where the big unknown is how the >>> vacuum energy is so small compared to what QFT predicts. Dark matter is not >>> homogeneous and isotropic as is dark energy that is presumed to give the de >>> Sitter-like expansion curvature. Yet it is still possible that dark energy >>> is some vacuum type of physics. I have pondered that the large energy >>> excess we expect for dark energy might in fact be some localized form of >>> vacuum energy that condensed in the early universe, and this excess remains >>> as DM. >>> >>> The phenomenologies proposed so far seem to be falling apart. WIMPs are >>> mostly likely ruled out. Sterile neutrinos appear to be gone. Axions remain >>> a possibility, though so far attempts to detect them have come up null. As >>> a result the most honest thing that can be said is we really have no >>> certainty about the nature of DM. >>> >>> LC >>> >>> -- >>> >> You received this message because you are subscribed to the Google Groups >>> "Everything List" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> >> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/everything-list/f24dd18e-7185-4cf5-88a7-9e3444da6642n%40googlegroups.com >>> <https://groups.google.com/d/msgid/everything-list/f24dd18e-7185-4cf5-88a7-9e3444da6642n%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/e126d7f2-a194-4a6b-80f7-757e38088b00n%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/e126d7f2-a194-4a6b-80f7-757e38088b00n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAPCWU3KOPD8Otz06Vt6YoJm956Vr%2By8ux%2B27gnJxskmpTzOOGQ%40mail.gmail.com.
