2003/03/31 by A. P. Bakulev, Alexander P. Bakulev, С. В. Михайлов +2 · 3 citations
Physics and Astronomy · #Amplitude #High-Energy Particle Collisions Research #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #QCD sum rules #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum electrodynamics #Quantum mechanics #hep-ph
paper · pdf · doi:10.1016/j.physletb.2003.10.033
published as Phys.Lett.B578:91-98,2004 · 11 pages, 5 figures as EPS files. 2 figures added; discussion of NNLO effects added and discussion of twist-4 uncertainties expanded; some typos corrected; physics unchanged; some references added. Matches version to appear in PLB
arxiv created 2003/10/10 · openalex publication_date 2003/11/06 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The CLEO experimental data on the πγ transition are analyzed to next-to-leading order accuracy in QCD perturbation theory using light-cone QCD sum rules. By processing these data along the lines proposed by Schmedding and Yakovlev, and recently revised by us, we obtain new constraints for the Gegenbauer coefficients a2 and a4, as well as for the inverse moment 〈x−1〉π of the pion distribution amplitude (DA). The former determine the pion DA at low momentum scale, the latter is crucial in calculating pion form factors. From the results of our analysis we conclude that the data confirm the end-point suppressed shape of the pion DA we previously obtained with QCD sum rules and nonlocal condensates, while the exclusion of both the asymptotic and the Chernyak–Zhitnitsky DAs is reinforced at the 3σ- and 4σ-level, respectively. The reliability of the main results of our updated CLEO data analysis is demonstrated. Our pion DA is checked against the di-jets data from the E791 experiment, providing credible evidence for our results far more broadly.