Nonperturbative Aspects of Hadron Structure Phenomenology
The effort to gain a more thorough understanding of hadronic structure has enjoyed considerable gains in recent years, and, with the imminent 12 GeV upgrade at Jefferson Lab, on-going work at facilities like J-PARC, and a possible electron-ion collider, more rapid progress appears forthcoming. Much of this work principally seeks a better control over the partonic substructure of strongly-interacting matter, which is nonperturbative at momenta below the confinement scale. In this talk I will discuss the various nonperturbative effects that complicate experiments -- particularly DIS; these include so-called sub-leading corrections in Q2, dynamical higher twist effects, and hadron mass corrections. I will also discuss calculations and searches for several examples of flavor symmetry violation, which also originate in the nonperturbative properties of QCD at low momenta, and conclude with some recent computations related to the possibility of nonperturbative heavy quarks in the nucleon.