A symmetry-preserving continuum approach to the two valence-body bound-state problem is used to calculate the valence, glue and sea distributions within the pion; unifying them with, inter alia, electromagnetic pion elastic and transition form factors. The analysis reveals the following momentum fractions at the scale $zeta_2:=2,$GeV: $langle x_{ m valence} angle = 0.48(3)$, $langle x_{ m glue} angle = 0.41(2)$, $langle x_{ m sea} angle = 0.11(2)$; and despite hardening induced by the emergent phenomenon of dynamical chiral symmetry breaking, the valence-quark distribution function, ${q}^pi(x)$, exhibits the $xsimeq 1$ behaviour predicted by quantum chromodynamics (QCD). After evolution to $zeta=5.2,$GeV, the prediction for ${q}^pi(x)$ matches that obtained using lattice-regularised QCD. This confluence should both stimulate improved analyses of existing data and aid in planning efforts to obtain new data on the pion distribution functions.
Drawing insights from pion parton distributions
Minghui Ding;Daniele Binosi;
2020-01-01
Abstract
A symmetry-preserving continuum approach to the two valence-body bound-state problem is used to calculate the valence, glue and sea distributions within the pion; unifying them with, inter alia, electromagnetic pion elastic and transition form factors. The analysis reveals the following momentum fractions at the scale $zeta_2:=2,$GeV: $langle x_{ m valence} angle = 0.48(3)$, $langle x_{ m glue} angle = 0.41(2)$, $langle x_{ m sea} angle = 0.11(2)$; and despite hardening induced by the emergent phenomenon of dynamical chiral symmetry breaking, the valence-quark distribution function, ${q}^pi(x)$, exhibits the $xsimeq 1$ behaviour predicted by quantum chromodynamics (QCD). After evolution to $zeta=5.2,$GeV, the prediction for ${q}^pi(x)$ matches that obtained using lattice-regularised QCD. This confluence should both stimulate improved analyses of existing data and aid in planning efforts to obtain new data on the pion distribution functions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
