Details

Autor(en) / Beteiligte

• Chang, L
• Cloët, I C
• Roberts, C D
• Schmidt, S M
• Tandy, P C

Titel

Pion electromagnetic form factor at spacelike momenta

Ist Teil von

• Physical review letters, 2013-10, Vol.111 (14), p.141802-141802, Article 141802

Ort / Verlag

United States

Erscheinungsjahr

2013

Quelle

American Physical Society

Beschreibungen/Notizen

• 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.