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I Moriond EW 2017 results -- No supersymmetry

  1. Mar 20, 2017 #1
    52nd Rencontres de Moriond EW 2017
    présidé par Lydia Iconomidou-Fayard (LAL), Jean Marie Frere (ULB Brussels)

    has released results based on 36 fb-1 data @ 13 TEV

    they compare predictions from SUSY i.e squarks gluinos stops etc, with SM

    all results consistent with SM 95%

    No supersymmetry

    given that most discoveries are found fairly early in data collection at hadron colliders
    given they found no gluinos and squarks and supersymmetry in the first 36 fb-1 data
    what are the propsects of ever finding these over LHC lifetime of projected 3000 fb-1 data

    what are implications to MSSM and nMSSM that no SUSY was found.

    what are implications to natural SUSY that no SUSY was found @ 13 TEV

    is natural SUSY still viable or has data falsified it?

    how does it affect SUSY and string theory that LHC has failed to find any evidence of SUSY after analyzing 36 fb-1 @ 13 TEV energies?

    does solutions to Higgs hiearchy problem - SUSY technicolor extra dimensions require finding new physics @ LHC energies?

    LHC results are consistent with SM only. no evidence of technicolor or extra dimesions RS gravitons dark matter neutralinos SUSY were found by LHC either. what does this mean for higgs hiearchy problem that motivates new physics searches?
    does not finding SUSY bolster loops LQG over strings?
  2. jcsd
  3. Mar 20, 2017 #2


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    Read the papers. I know you will understand them.
    Both ATLAS and CMS have public projections how much they can do with 3000/fb, and theorists have similar projections as well.
  4. Mar 20, 2017 #3
    one of the papers had a statement to imagine 3000 fb-1 @ 100 TEV resolving many issues.

    another paper had a statement iirc that ruling out gluinos from 1200-1600 gev makes it impossible for a discovery in that mass range with 5-sigma

    and one paper had a statement that 36 fb-1 @ 13 TEV allowed for better precision then the expected 14 TEV @ 3000 fb-1 on certain rule outs.
  5. Mar 20, 2017 #4
    Can I emphasize first that the preferred language for particle physics is field theory, not strings or loops. QFT is the language of the SM and of every BSM model that makes collider predictions.

    String theory can definitely reduce to field theory. The search for a string model of reality, is all about that. LQG, on the other hand... Their main priority is still just, getting space-time itself. Then there are well-known problems like their peculiar method of quantization (polymer quantization), which doesn't even give you the simple harmonic oscillator as it appears in QFT, and their problems with fermions and black hole entropy.

    String theorists have a vast space of models to explore. Loop theorists don't even have a functioning model that clearly reproduces any QFT at all, let alone the SM. The one thing in loop-world that interests me is the work on twistor networks, which might converge on the rewriting of QFT in twistor variables that grew out of Penrose's twistor program and Witten's twistor string.

    About SUSY - that LQG usually doesn't feature SUSY, is mostly just another symptom of LQG's limitations. Regarding strings, yes string theory is full of SUSY, but there's nothing in string theory that implies SUSY breaking at low energies; people assumed that, and looked for it, because they thought it was the solution to the hierarchy problem. But strings can also have SUSY broken at high scales, or even no SUSY at all.
  6. Mar 20, 2017 #5
    How can strings have no SUSY at all since bosonic string theory doesn't describe our world.

    Current experimental results is consistent with NO SUSY no extra dimensions. without either, there's no credible case for string theory.
  7. Mar 21, 2017 #6
    There are actually vast numbers of non-supersymmetric string vacua. They contain fermions, and may exhibit SUSY-like relations between fermions and bosons, but are not supersymmetric. They have been relatively neglected because they are usually unstable, because SUSY makes calculation easier, and because SUSY just seemed too good to not be true; but they have been studied a little. This paper is a small step towards at a minimalism similar to nuMSM + asymptotic safety. They don't exhibit a model with just the SM fields (there are other papers heading in that direction), but they do tackle Higgs inflation.
  8. Mar 21, 2017 #7


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    Any other news of Moriond? Everything is looking very SM-ish.
  9. Mar 21, 2017 #8


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    Still ongoing, and we'll have Moriond QCD after that. Nothing surprising so far.
  10. Mar 21, 2017 #9


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    No, because it is unclear if LQG has gravity.
  11. Mar 21, 2017 #10
    Penn state is AFAIK the only LQG program both faculty and training graduate students in US.

    in light of LHC not finding any evidence of SUSY or any hints of BSM, even after collecting and analyzing 36 fb-1 @ 13 TEV perhaps it's time for the top physics departments in the world and research centers in Princeton, Harvard Stanford MIT UC Berkley et al, hire and train more loop LQG researchers so the issue of whether it is unclear LQG has gravity can be made more clear with more researchers and theorists and grad students working on this in both faculty and graduate programs.
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