SOFFERS INEQUALITY

Various issues surrounding a recently proposed inequality among twist- two quark distributions in the nucleon are discussed. We provide a rig orous derivation of the inequality in QCD, including radiative correct ions and scale dependence. We also give a more heuristic, but more phy sical derivation, from which we show that a similar inequality does no t exist among twist-three quark distributions. We demonstrate that the inequality does not constrain the nucleon's tensor charge. Finally we explore physical mechanisms for saturating the inequality, arguing it is unlikely to occur in nature.