The end of WHAT nucleon-spin crisis?
  Povh and Walcher have written a paper entitled "The end of the nucleon-spin crisis" [arXiv:1603.05884]. But there is no such crisis. What appeared to be a spin crisis in the parton model, 28 years ago, was a consequence of a misinterpretation of the results of the famous European Muon Collaboration experiment on polarized deep inelastic scattering. It would thus seem that Povh and Walcher have invoked a somewhat dubious argument based on hadronic fluctuations of the photon in order to resolve a non-existent problem. 
Elliot Leader
hep-ph hep-ex