The problem is that neither the LHC nor its recently decommissioned American counterpart, the Tevatron, have seen any strong evidence for new, heavy particles during their experiments. Though they keep searching at higher energy ranges, the particle accelerators don’t turn up any new superpartners.I think that if the LHC sees no indication of supersymmetry, the theory in its present form, will lose much of its appeal.
“As we exclude more and more energy ranges, the supersymmetry models that most easily keep the scales separate get more and more contrived,” said Krauss.
Already, experiments have excluded the simplest supersymmetric theories. Physicists can keep tweaking their theories but after a while these fine-tunings begin to seem arbitrary.