Is supersymmetry in super-trouble?

The Standard Model, and even moreso string theory, have tried since the 1970s to incorporate supersymmetry or "SUSY" to solve various issues. SUSY postulates that the particles we observe have counterpart particles on the other side of the fermion-boson (loosely "matter-force") divide, so that instead of the seeming discrepancy between 12 fermions and 4 bosons that make up everything, there would be a "supersymmetry." (That sentence is probably too amateurish to be correct, but there is always Wikipedia.)

Anyway, one of the perks of the Large Hadron Collider was supposed to be testing whether SUSY really exists, or rather, existed back when the universe was a livelier place. Signs point to "no":

SUSY's utility and mathematical grace have instilled a "religious devotion" among its followers, says Adam Falkowski, a theorist at the University of Paris-South in France. But colliders have failed to turn up direct evidence of the super particles predicted by the theory. The Tevatron at the Fermi National Accelerator Laboratory in Batavia, Illinois, for example, has found no evidence of supersymmetrical quarks ('squarks') at masses of up to 379 gigaelectronvolts (energy and mass are used interchangeably in the world of particle physics).

The LHC is now rapidly accumulating data at higher energies, ruling out heavier territory for the super particles. This creates a serious problem for SUSY (see 'SUSY's mid-life crisis'). As the super particles increase in mass, they no longer perfectly cancel out the troubling quantum fluctuations that they were meant to correct. Theorists can still make SUSY work, but only by assuming very specific masses for the super particles — the kind of fine-tuning exercise that the theory was invented to avoid. As the LHC collects more data, SUSY will require increasingly intrusive tweaks to the masses of the particles.

So far the LHC has doubled the mass limit set by the Tevatron, showing no evidence of squarks at energies up to about 700 gigaelectronvolts. By the end of the year, it will reach 1,000 gigaelectronvolts — potentially ruling out some of the most favoured variations of supersymmetry theory.

As the article goes on to note, some folks' 30 years of studying SUSY could begin to look rather pointless, not to mention a crash in their Nobel futures. Most attempts at string theories also require SUSY, so this could be bad news for those guys as well.

(Via, who else, 3QD.)