For the latest SUSY enthusiast take on the implications of what the LHC has been (not) seeing, your best bet might be yesterday’s talk at the KITP by Nima Arkani-Hamed on Naturalness. An hour and 40 minutes, no slides, nothing much on the blackboard, just him talking about how he now sees things. Some high points:
- If the Higgs turns out to have spin two, he’ll quit physics.
- If the Higgs turns out to be a techni-dilaton, he’ll kill himself.
- At this point, a natural theory would have to be rather baroque, so he favors abandoning naturalness in favor of simplicity.
- The simplest thing is the Standard Model, but that requires too much fine-tuning. He won’t completely abandon naturalness: one part in a million fine-tuning is fine, but the SM fine-tuning problem isn’t. This is the point where he loses me (going from the SM to the vastly more complicated SUSY theories with the needed SUSY breaking seems to me not close to being worth the supposed improvement in the fine-tuning).
- He complains that “Some BSM theorists are giving our field a bad name” by repeatedly making SUSY predictions that turn out to be wrong and changing their story.
- He’s not one of those: he still favors split SUSY, and has since 2004.
- Split SUSY makes a falsifiable prediction: no Higgs gamma-gamma excess. This is of course the same prediction as the Standard Model.
- In his favored version of split SUSY, all SUSY partners are much too heavy to ever be observable except the wino, bino and gluino. He had a lot to say about what observing these would tell us, but not much about what the implications are of not seeing them in the LHC 8 TeV run. Would this just mean “surely they’ll show up at 13 TeV”? Is seeing nothing at 8 TeV consistent with split SUSY? What about seeing nothing at 13 TeV?
In any case, giving up on SUSY is definitely not on the agenda as far as he’s concerned.