Parton distribution amplitudes: Revealing correlations within the proton and Roper
Year: 2018
Type: article
Abstract: Constrained by solutions of the continuum three-valence-body bound-state equations, we use perturbation theory integral representations (PTIRs) to develop algebraic Ansätze for the Faddeev wave functions of the proton and its first radial excitation, delivering therewith a quantum field theory calculation of the pointwise behaviour of their leading-twist parton distribution amplitudes (PDAs). The proton's PDA is a broad, concave function, with its maximum shifted relative to the peak in QCD's conformal limit expression for this PDA. The size and direction of this shift signal the presence of both scalar and pseudovector diquark correlations in the nucleon , with the scalar generating around 60% of the proton's normalisation. The radial-excitation is constituted similarly, and the pointwise form of its PDA, which is negative on a material domain, is the result of marked interferences between the contributions from both types of diquark; particularly, the locus of zeros that highlights its character as a radial excitation. These features originate with the emergent phenomenon of dynamical chiral-symmetry breaking in the Standard Model .
Source: Physics Letters B
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
Funders: U.S. Department of Energy, European Commission, Ministry of Education of the People's Republic of China, Ministerio de Economía y Competitividad, Ministerio de Asuntos Económicos y Transformación Digital, Gobierno de España, Recruitment Program of Global Experts, Office of Science, Horizon 2020 Framework Programme, Nuclear Physics, Argonne National Laboratory
Awards: G102163711, G107546177, G1313983767, G1664757510, G1760870335, G2116931927, G2287611682, G262962599, G2896472831, Opening Sphere UAB-CEI to PostDoctoral Fellows, G3075337988, G434337789, G4833470993, G498139845, G5523129336, G5793545902, G6256534168, G6848031779, G6918803902, G969889393, G993149817
OpenAlex ID: W2769484378