We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
The pion transition form factor and the pion distribution amplitude.
- Authors
Noguera, S.; Vento, V.
- Abstract
Recent BaBar data on the pion transition form factor, whose Q-dependence is much steeper then predicted by asymptotic Quantum Chromodynamics (QCD), have caused a renewed interest in its theoretical description. We present here a formalism based on a model-independent description for low photon virtuality and a high photon virtuality description based on QCD, which match at a scale Q. The high photon virtuality description incorporates a flat pion distribution amplitude, $ \phi$( x) = 1 , at the matching scale Q and QCD evolution from Q to Q > Q . The flat pion distribution is connected, through soft pion theorems and chiral symmetry, to the pion valence parton distribution at the same low scale Q. The procedure leads to a good description of the data, and by incorporating additional twist-three effects, to an excellent description of the data.
- Subjects
QUANTUM chromodynamics; PION-pion interactions; PHOTONS; CHIRALITY of nuclear particles; FORM factor (Nuclear physics)
- Publication
European Physical Journal A -- Hadrons & Nuclei, 2010, Vol 46, Issue 2, p197
- ISSN
1434-6001
- Publication type
Article
- DOI
10.1140/epja/i2010-11029-6