The particle collider's first run at new energies has a hint of a signal. Supersymmetry may be out but String Theory could still be in play.
The Standard Model unifies all the forces except gravity, which is 1032 times weaker than anything else. Nobody knows why, leaving physicists stuck with what's been termed a hierarchy problem—why are the forces arranged as they are? One stab at solving this problem, developed by Lisa Randall and Raman Sundrum, relied on ideas from string theory. Randall–Sundrum models posit extra dimensions and branes that represent particles in our Universe. One of those particles is a graviton, a theoretical particle that helps mediate gravitational force.