For every particle, there is a partner: a superparticle or “sparticle.”
So how does string theory banish the quantum corrections that have bedeviled physicists for decades? String theory possesses something called “supersymmetry.” For every particle, there is a partner: a superparticle or “sparticle.” For example, the partner of the electron is the “selectron.” The partner of the quark is the “squark.” So we have two types of quantum corrections, those coming from ordinary particles and those from the sparticles. The beauty of string theory is that the quantum corrections coming from these two sets of particles exactly cancel each other out.
