The 1.4 GeV J^PC = 1^-+ state as an interference of a non-resonant   background and a resonance at 1.6 GeV
  We investigate theoretical interpretations of the 1.4 GeV J^PC exotic resonance reported by the E852 collaboration. A K-matrix analysis shows that the 1.4 GeV enhancement in the E852 eta pi data can be understood as an interference of a non-resonant Deck-type background and a resonance at 1.6 GeV. 
Alexander Donnachie and Philip R. Page