Dual-current amplitudes with spurious states

1971
31 pages
Published in:
  • Nuovo Cim.A 4 (1971) 299-329

Citations per year

197219771982198719923021
Abstract: (Springer)
We analyse the possibility of constructing a model for current amplitudes satisfying i) planar duality, ii) complete factorization, iii) the divergence conditions of CVC and current algebra, and iv) the absence of unphysical singularities. The consistency of the points i), ii) and iii) requires the contribution of spurious states in the factorization of the two-current amplitudes. The point iv) is related to the off-shell extrapolation of the amplitudes and also shows the necessity of spurious states. We therefore suggest that spurious states must have a physical interpretation in terms of hadrons. We then consider in detail a specific model for the vector-current operator. The relevant current amplitudes are shown to have a good behaviour in the limit of zero-current momenta; the single-current amplitudes are dominated by the external line insertions and the two-current amplitudes satisfy the Ward-Takahashi divergence conditions. The two-current amplitudes, however, have a bad behaviour for arbitrary momenta, and also show a violation of CVC due to the presence of spurious-pole contributions.
  • duality
  • dual resonance model
  • model: conserved vector current
  • veneziano model: n-point function
  • current algebra
  • field theory
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