Regge Poles and Cuts in pi0 Photoproduction and Related Reactions
Sep, 197732 pages
Published in:
- Nucl.Phys.B 137 (1978) 413-444
- Published: 1978
Report number:
- MC/T/77/10
Citations per year
Abstract: (Elsevier)
A previous analysis of intermediate- and high-energy photoproduction data using finite-energy sum rules and fixed- t dispersion relations is extented to enable effects due to Regge poles and cuts to be distinguished. This is achieved by requiring Regge poles to be evasive and to have nonsense wrong signature zeros, whereas cuts are parametrised by effective two-pole forms and are taken to be self-conspiring with minimal structure in their residues. These constraints, together with phase information provided by data on the Primakoff effect, enable an essentially unique separation of pole and cut effects to be made. We compare our results with popular cut models of hadronic reactions relevant at accelerator energies, and with the universal impact parameter hypothesis. None of these are able to reproduce all the features we find in our amplitudes. Finally, we show how our results can cast light on the puzzling absence of dips in η 0 photoproduction and π 0 electroproduction, by making plausible assumptions about the isospin and q 2 dependences of our amplitudes, respectively.- PHOTON NUCLEON: INTERACTION
- INTERACTION: PHOTON NUCLEON
- PI0: PHOTOPRODUCTION
- PHOTOPRODUCTION: PI0
- PI0: ELECTROPRODUCTION
- ELECTROPRODUCTION: PI0
- ETA(549): PHOTOPRODUCTION
- PHOTOPRODUCTION: ETA(549)
- REGGE POLES
- REGGE CUT
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