Nucleon viewed as a Borromean Bound-State

摘要

We explain how the emergent phenomenon of dynamical chiral symmetry breakingensures that Poincar\'e covariant analyses of the three valence-quarkscattering problem in continuum quantum field theory yield a picture of thenucleon as a Borromean bound-state, in which binding arises primarily throughthe sum of two separate contributions. One involves aspects of the non-Abeliancharacter of Quantum Chromodynamics that are expressed in the strong runningcoupling and generate tight, dynamical color-antitriplet quark-quarkcorrelations in the scalar-isoscalar and pseudovector-isotriplet channels. Thisattraction is magnified by quark exchange associated with diquark breakup andreformation, which is required in order to ensure that each valence-quarkparticipates in all diquark correlations to the complete extent allowed by itsquantum numbers. Combining these effects, we arrive at a properlyantisymmetrised Faddeev wave function for the nucleon and calculate, e.g. theflavor-separated versions of the Dirac and Pauli form factors and the proton'sleading-twist parton distribution amplitude. We conclude that available dataand planned experiments are capable of validating the proposed picture.