A Simple Approach to the Reggeisation of Photoproduction
The theory of the Reggeisation of photonic processes is in a very peculiar state, despite the appearance of many papers on the subject. The problem of Gauge Invariance, the question of whether the π pole is kinematical or dynamical and the singularity of the Regge residue combine to produce a situation in which the usual “rules for Reggeisation” lead to unsatisfactory results.
KeywordsFeynman Diagram Gauge Invariance Helicity Amplitude Residue Function Dynamical Singularity
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- (1c).J. P. Adler and M. Capdeville, Nucl. Phys. 83, 637 (1967)Google Scholar
- (1i).P. D. B. Collins and F. D. Gault, Durham University Preprint, March 1970.Google Scholar
- 2.Compare e.g. Refs. 1(a), 1 (g), 1(h) and 1(i).Google Scholar
- 3.We are working in the Lorentz gauge. It should be noted, when we come later to talk about Feynman diagrams, that a one-to-one correspondence between a diagram and a mathematical expression exists if and only if the Gauge is specified. The diagrams have no independent meaning until the Gauge is chosen. This fact is often overlooked and can lead to confusion.Google Scholar
- 4.The strongest argument against a fixed pole is a phenomenological one, (which is thus really relevant to photoproduction from nucleons with spin, and not to the artificial case being considered here) namely that if a fixed pole at J=0 exists we would get da/dtas-2, whereas experimentally s2 da/dt seems to be decreasing with increasing s.Google Scholar
- 5.For a review of the problem of Daughters and Conspiracies see: E. Leader, Boulder Summer School Lectures (1969).Google Scholar
- 8.It is of interest to note that eqs. (55) when added together, are exactly equivalent to the superconverence relation, of M. B. Halpern, Phys. Rev. 160, 1441 (1967).Google Scholar
- 9.See Ref. 1(e). Further work along these lines is being carried out in collaboration with J. Hanzal and P. G. Williams.Google Scholar