Abstract
A novel method is employed to compute the pion electromagnetic form factor, , 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 underestimates the full computation by just 15% on , in stark contrast to the result obtained using the asymptotic PDA. The analysis shows that hard contributions to the pion form factor dominate for , but, even so, the magnitude of reflects the scale of dynamical chiral symmetry breaking, a pivotal emergent phenomenon in the standard model.
- Received 1 July 2013
DOI:https://doi.org/10.1103/PhysRevLett.111.141802
© 2013 American Physical Society