We test application of the maximum entropy method to decompose the states
contributing to the unstable σ correlation function through the spectral
function in the four dimensional O(4) ϕ4 theory. Reliable results are
obtained for the σ mass and two-particle ππ state energy using
only the σ correlation function. We also find that the property of the
σ particle is different between the unstable (mσ/mπ>2)
and stable (mσ/mπ<2) cases.Comment: Lattice2002(spectrum), 3 page