Recent CLAS photoproduction results using a tagged bremsstrahlung photon beam for the ground-state pseudoscalar meson photoproduction channels (K+Λ, K+Σ0, ηp, π+n and π0p) show a normalization discrepancy with older results from SLAC, DESY and CEA that used an untagged bremsstrahlung beam. The CLAS results are roughly a factor of two smaller than the older data. The CLAS K+Λ and K+Σ0 results are in excellent agreement with the latest LEPS results that also employed a tagged beam. For the vector meson (ωp and ϕp) channels, CLAS agrees with SLAC results that employed a linearly polarized beam using laser back-scattering, as well as Daresbury data that also came from tagged photon experiment. We perform a global survey of these normalization issues and stress on their significant effect on the coupling constants used in various partial wave analyses.
@article{arxiv.1106.0479,
title = {Normalization discrepancies in photoproduction reactions},
author = {Biplab Dey and Curtis A. Meyer},
journal= {arXiv preprint arXiv:1106.0479},
year = {2011}
}
Comments
This expands upon a talk given at NSTAR'11. It is also a preliminary draft only