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Phenomenological aspects of ultra-high-energy collisions

  1. Sep 4, 2009 #1
    I have been studying the future physics, well, high-energy experiments that will succeed LHC, sLHC, ILC, CLIC, LHeC, etc. Experiments that will complete the electroweak theory and the Standard Model with very high precision and help toward supersymmetry, extra-dimensions, dark matter, dark energy, and grand unification theory.

    What scenarios should be beneficial at energies from 1 TeV to 200,000,000 TeV+, and how about making a list of possible advancements and discoveries?

    By the way, I am researching on very-high acceleration gradients, perhaps 100 times more powerful than prototype laser/plasma wakefield accelerators.

    A drawing of a 200,000,000 TeV center-of-mass energy accelerator.

    Last edited: Sep 4, 2009
  2. jcsd
  3. Sep 4, 2009 #2
    Nice art. This would make a nice logo. But if the large synchrotrons are optimally designed with the highest possible fields (including magnetic field strength and synchrotron radiation limits) then the sharp bends in the extraction lines are much too tight. You might have to extract to the outside of the rings. It might even eliminate the extraction bends altogether.
  4. Oct 6, 2009 #3
    On the immediate horizon, around 1TeV, an e+ e- linear collider could probe super symmetry models (where every "normal" particle is paired with another, higher mass particle that differs in spin by 1/2). Information from the LHC *should* give us some clues as to what's going on here. Either it will find something, which would help set the energy scales, or it won't, and we'll either need to search higher energies or give up on susy (the latter of which is unlikely to happen).

    Some cool stuff that ultra-high energy machines *might* be able to do is see if there is a real limit to how massive particles can get. Suppose, for fun, we find SUSY does happen. What is the heaviest particle in this new batch? What would we do if we found something beyond SUSY?? super-SUSY? lol Maybe one would even discover a new fundamental force!

    I suppose the likelihood of black-hole creation goes up significantly as well.

    Keep in mind, when you are trying to do precision physics, sometimes higher energy is not better. Some of the best ways to explore the mass of a particle is to "sweep" the energies very near the edge where the particle is created.

    Hmm, imagine the challenges of designing detectors for this!
  5. Oct 13, 2009 #4
    Highly speculative (Experiments that will), but that is the general hope/goal.

    The first step is the observance of the Higg's boson, which should already have been found, but has not. So they hope it will apear at higher energies and back fill the theory to result in the energy at which it is found.
  6. Oct 17, 2009 #5
    There are problems with circular accelerators for both electron and proton synchrotrons, as your artwork depicts.
    The synchrotron radiation for electrons is very high (even at 100 GeV), requires a lot of RF power, and damages accelerator components (radiation damage).
    Protons can be accelerated in superconducting synchrotrons, like the Fermilab Tevaron. In synchroton mode, it could accelerate 150 GeV protons to about 1 TeV in 20 seconds. In the CERN LHC (a superconducting ring with a cold (2 kelvin) beam tube), the proton synchrotron radiation, with a critical energy in the range of 40 to 60 eV (I think), desorbs residual gas molecules from the beam tube wall, leading to a rise in the beam tube vacuum. The small diameter of the beam tube, its temperature, and distance between vacuum pumps, makes pumping the vacuum very difficult.
    This is why future extreme energy accelerators (if any) will be linear.
    Bob S
  7. May 29, 2010 #6


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    Also, I have been told by people working on analyzing data from the LHC that they much prefer lepton colliders to hadron colliders. Apparently the data from LEP, which collided electrons and positrons, was very much cleaner than the data from the LHC. Since leptons are elementary particles, the resulting products are much simpler than with hadron collisions, because hadrons are composite particles made of quarks and gluons. Since extracting data from a collider involves sorting through huge numbers of events to find the few that you are looking for, cleaner data is a big deal. So a linear collider of either electrons and positrons or muons and anti-muons seems like a more logical next step than another hadron collider. Comments, anyone?
  8. May 29, 2010 #7
    It's true, lepton-lepton collisions are much nicer to deal with. Plus *all* center of mass beam energy is available to make a particle (which is generally not the case for hadrons). You need to have much more energy in your hadron beam than the energy of physics you are actually exploring.

    There has been some talk about muon colliders. The nice thing here is it's lepton-lepton, but since they are much more massive, you can in principle accelerate them in a circular ring.

    See: http://www.fnal.gov/pub/muon_collider/why-muons.html
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