We give a bilocal field theory description of a composite scalar with an extended binding potential,
that reduces to the Nambu–Jona–Lasinio (NJL) model in the pointlike limit. This provides a
description of the internal dynamics of the bound state and features a static internal wave-function,
ϕ(⃗r), in the center-of-mass frame that satisfies a Schr¨odinger-Klein-Gordon equation with eigenvalues
m2. We analyze the “coloron” model (single perturbative massive gluon exchange) which yields a
UV completion of the NJL model. This has a BCS-like enhancement of its interaction, ∝ Nc the
number of colors, and is classically critical with gcritical remarkably close to the NJL quantum
critical coupling. Negative eigenvalues for m2 lead to spontaneous symmetry breaking, and the
Yukawa coupling of the bound state to constituent fermions is emergent.