Charting the evolution of the strong interaction’s degrees of freedom

Abstract

Knowledge of theUniverse as constructed by human beings can be thought to be organized at varying scales of observation to tackle its complexity. Implicit in such an approach is the idea of a smooth evolution of knowledge between scales and, therefore, access to how Nature constructs the visible Universe, beginning from its most fundamental constituents. New and, in a sense, fundamental phenomena may typically be emergent as the scale of observation changes. The study of the Strong Interactions, which is responsible for the contruction of the bulk of the visible matter in the Universe (98% by mass), in this sense, is a labor of exploring evolutions and unifying aspects of its knowledge found at varying scales: from interaction of quarks and gluons as represented by the theory of pQCD at high four momentum transfers (Q2) to emerging dressed quark and even meson-baryon degrees of freedom mostly described by effective models as Q2 decreases. In this paper we will introduce a collaborative research framework that is directly dedicated to this effort and note how our ongoing experimental analysis—extraction of observables from electroproduction of π+π off the proton—will provide data towards this end.