Pion distribution functions from low-order Mellin moments
Ya Lu (Department of Physics, Nanjing Tech University, Nanjing, China)
; Yin-Zhen Xu (Dpto. Ciencias Integradas, Centro de Estudios Avanzados en Fis., Mat. y Comp., Fac. Ciencias Experimentales, Universidad de Huelva, Huelva, Spain, Dpto. Sistemas Físicos, Químicos y Naturales, Univ. Pablo de Olavide, Sevilla, Spain)
; Khépani Raya (Dpto. Ciencias Integradas, Centro de Estudios Avanzados en Fis., Mat. y Comp., Fac. Ciencias Experimentales, Universidad de Huelva, Huelva, Spain)
; Craig D. Roberts (School of Physics, Nanjing University, Nanjing, China, Institute for Nonperturbative Physics, Nanjing University, Nanjing, China)
; José Rodríguez-Quintero (Dpto. Ciencias Integradas, Centro de Estudios Avanzados en Fis., Mat. y Comp., Fac. Ciencias Experimentales, Universidad de Huelva, Huelva, Spain)
Exploiting an evolution scheme for parton distribution functions (DFs) that is all-orders exact, contemporary lattice-QCD (lQCD) results for low-order Mellin moments of the pion valence quark DF are shown to be mutually consistent. The analysis introduces a means by which key odd moments can be obtained from the even moments in circumstances where only the latter are available. Combining these elements, one arrives at parameter-free lQCD-based predictions for the pointwise behaviour of pion valence, glue, and sea DFs, with sound uncertainty estimates. The behaviour of the pion DFs at large light-front momentum fraction, , is found to be consistent with QCD expectations and continuum analyses of pion structure functions, i.e., damping like , with , , . It may be possible to test these predictions using data from forthcoming experiments.