title: Pion electromagnetic form factor at spacelike momenta.
abstract: A novel method is employed to compute the pion electromagnetic form factor, F(π)(Q²), on the entire domain of spacelike momentum transfer using the Dyson-Schwinger equation (DSE) framework in QCD. The DSE architecture unifies this prediction with that of the pion's valence-quark parton distribution amplitude (PDA). Using this PDA, the leading-order, leading-twist perturbative QCD result for Q²F(π)(Q²) underestimates the full computation by just 15% on Q²≳8 GeV², in stark contrast to the result obtained using the asymptotic PDA. The analysis shows that hard contributions to the pion form factor dominate for Q²≳8 GeV², but, even so, the magnitude of Q²F(π)(Q²) reflects the scale of dynamical chiral symmetry breaking, a pivotal emergent phenomenon in the standard model.
authors.affiliation: Institut für Kernphysik, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Chang
authors.forename: I C
authors.initials: IC
authors.lastname: Cloët
authors.forename: C D
authors.initials: CD
authors.lastname: Roberts
authors.forename: S M
authors.initials: SM
authors.lastname: Schmidt
authors.forename: P C
authors.initials: PC
authors.lastname: Tandy