Three body unitary coupled channel analysis on η (1405/1475)

The new BESIII data on J / ψ → γη (1405/1475) → γKK¯π is more precise than before. A three-body unitary coupled-channel analysis of experimental Monte Carlo outputs for J / ψ → γη (1405/1475) → γKK¯π is introduced. This model does not only fit the γKK¯π Dalitz plot distributions but also the branching ratios of “γππη” and “γγππ” final states relative to that of “ γKK¯π ”. After fitting, we successfully extract the η(1405/1475) pole locations. The η(1405/1475) states are described by two bare states dressed with continuum states. At last, we post predict the distribution of J /ψ → γη(1405/1475) → γππη, γπππ, γγππ.