DSE inspired model for the pion's valence dressed-quark GPD

4th Symposium on Prospects in the Physics of Discrete Symmetries

Chang, L.^1 ; Mezrag, C.^2 ; Moutarde, H.^2 ; Roberts, C.D.^3 ; Rodríguez-Quintero, J.^4 ; Sabatié, F.^2

CSSM, School of Chemistry and Physics, University of Adelaide, Adelaide

SA

5005, Australia^1

Centre de Saclay, IRFU/Service de Physique Nucleaire, Gif-sur-Yvette

F-91191, France^2

Physics Division, Argonne National Laboratory, Argonne

IL

60439, United States^3

Departamento de Física Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, Huelva

E-21071, Spain^4

关键词: Impact-parameter;    Impulse approximation;    Parton distributions;    Quark structure;    Radon Transform;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/631/1/012062/pdf
DOI  :  10.1088/1742-6596/631/1/012062

来源: IOP

【 摘 要 】

We sketch here an approach to the computation of genaralised parton distributions (GPDs), based upon a rainbow-ladder (RL) truncation of QCD's Dyson-Schwinger equations and exemplified via the pion's valence dressed-quark GPD, Hvπ(x,ξ,t). Our analysis focuses on the case of zero skewness, ξ = 0, and underlines that the impulse-approximation used hitherto to define the pion's valence dressed-quark GPD is generally invalid owing to omission of contributions from the gluons which bind dressed-quarks into the pion. A simple correction enables us to identify a practicable improvement to the approximation for Hvπ(x,0,t), expressed as the Radon transform of a single amplitude. Therewith we obtain results for Hvπ(x,0,t) and the associated impact-parameter dependent distribution, , which provide a qualitatively sound picture of the pion's dressed-quark structure at an hadronic scale.