2000/01/29 by M. I. Levchuk, M.I. Levchuk, M. Schumacher +1 · 1 citation
Physics and Astronomy · #Nuclear physics research studies #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #nucl-th
paper · pdf · doi:10.1016/s0375-9474(00)00185-8
published as Nucl.Phys. A675 (2000) 621-636 · 17 pages, 7 figures, revtex. Submitted to Nucl. Phys. A
arxiv created 2000/01/29 · openalex publication_date 2000/08/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Neutral pion photoproduction on the deuteron in the inelastic channel is studied in the threshold region from 142 to 160 MeV. The calculation is based on the use of the diagrammatic approach. Contributions from the pole diagrams, one-loop diagrams both with n-p and π-N rescattering as well as two-loop diagrams with simultaneous inclusion of these rescattering mechanisms are taken into account. We have found a reasonable agreement with a very simple calculation by J.C. Bergstrom et al. [Phys. Rev. C 57 (1998) 3203]. It is shown that the `effective' electric dipole deuteron amplitude Ed is negative in agreement with a prediction of ChPT. We conclude that a deviation of about 20% from a ChPT prediction for Ed discovered in an experiment on coherent π0 photoproduction off the deuteron cannot be attributed to inadequate estimates of inelastic channel contributions. We suggest that π-N rescattering is responsible for the deviation of the free-nucleon p1 threshold amplitude from the value measured in that experiment