Exploring the Range of Energy for SUSY Particles

[Jimmy84]

I recently read the blog of Philip Gibbs, it seems to have some interesting arguments.

http://blog.vixra.org/2013/07/18/naturally-unnatural/

... we have learned that the mass of the Higgs boson is around 125 GeV and that this lies near the minimum end of the range of masses that would allow the vacuum to be stable even if there are no new particles to help stabilize it. Furthermore we do indeed find no evidence of other new particles up to the TeV range and the Higgs looks very much like a lone standard model Higgs. Yes, there could still be something like SUSY there if it has managed to hide in an awkward place. There could even be much lighter undiscovered particles such as those hinted at by some dark matter searches, if they are hard to produce or detect at colliders, but the more obvious conclusion is that nothing else is there at these energies.
This is what many people called the “nightmare scenario” because it means that there are no new clues that can tell us about the next model for particle physics. Many theorists had predicted SUSY particles at this energy range in order to remove fine-tuning and have been disappointed by the results. Instead we have seen that the Higgs sector is probably fine tuned at least by some small factor. If no SUSY is found in the next LHC run at 13 TeV then it is fine-tuned at about the 1% level.

My question is what is the range of energies in which SUSY particles are predicted or expected to be found? can a 13 Tev range energy debunk Supersymmetry?

Theorist Nima Arkani-Hamed recently suggested that it would be worth building a 100 TeV hadron collider even if the only outcome was to verify that there is no new physics up to that energy, It would show that the Higgs mass is fine-tuned to one part in 10,000 and that would be a revolutionary discovery. If it failed to prove that it would find something less exciting such as SUSY.

What do you think about that?

 

[phinds]

What do you think about that?

I think that the funding for a 100TV collider is completely impossible in anything like the near term.

 

[tom.stoer]

Is there a precise relation between energy scale and cost?

 

[phinds]

Is there a precise relation between energy scale and cost?

I wouldn't know, but at 10X the power of the LHC, you've got to believe that the price tag would be WAY beyond anything that is politically acceptable to spend on something that unlikely to have any short term practical benefit.

 

[tom.stoer]

?.. you've got to believe that the price tag would be WAY beyond anything that is politically acceptable ...

I fully agree.

Nevertheless it would be interesting to know something like

$\text{cost}_\text{construction} = f(E)$

$\text{cost}_\text{operation} = g(E)$

 

[DimReg]

I fully agree.

Nevertheless it would be interesting to know something like

$\text{cost}_\text{construction} = f(E)$

$\text{cost}_\text{operation} = g(E)$

f and g are also (mostly decreasing) functions of time, so I think that's a very difficult question to answer. You could approximate it by taking the cost of the LHC and dividing by 14 TeV, which (using wikipedia data, which only tells me total budget) gives you $4.4 billion / 14 TeV ~ $300 Million / TeV. That doesn't include the cost of the experiments, but is the total projected cost for the collider itself. Per year, that's less than $30 Million/Tev Year.

Compare that to https://en.wikipedia.org/wiki/Northrop_Grumman_B-2_Spirit, which costs ~$700 Million per plane. For the total cost of that project, a 140 TeV (if f(E) is to be trusted at all) collider could have been constructed. By this I mean to point out that even though the LHC was expensive, its cost really wasn't that high on the scale of government expenditures. (Another costly USA military project for comparison https://en.wikipedia.org/wiki/F-22_Raptor).

 

[Harry Wilson]

I wouldn't know, but at 10X the power of the LHC, you've got to believe that the price tag would be WAY beyond anything that is politically acceptable to spend on something that unlikely to have any short term practical benefit.

Wasn't the SSC meant to be 40 TeV? I know that's less than half what's being asked, but I think it shows that the idea isn't that crazy. The LHC was built on top of preexisting facilities, so its energy was limited by old hardware which I suppose makes it difficult to compare to a hypothetical brand-new collider.