Preliminary results of Chew--Low extrapolations using π-p → π-π+n at 4.5 GeV/c

About 8,600 π−π+n events, from 110,000 2‐prong events, have been analyzed using several forms of Chew‐Low extrapolation. The results are compared on the basis of chi‐square probabilities, stability against change in the upper limit in ‐t used smoothness of σππ as a function of Mππ, and agreement with the unitarity limit for σππ at the ρ mass.