0 A New Decomposition of ππ S - wave Interaction ∗
نویسندگان
چکیده
The experimental isoscalar ππ → ππ S-wave amplitude squared below 1.75 GeV is characterized by a very broad structure f0(4001200) with two narrow dips due to its destructive interference with the f0(980) and f0(1500). The f0(1370) and f0(1710) do not show up clearly in the ππ → ππ S-wave amplitude due to their weak coupling to ππ. This paper is about the controversial nature of the broad f0(400-1200). We decompose it into two parts, i.e., t-channel ρ meson exchange plus an additional s-channel resonance f0(X). With the tchannel ρ meson exchange fixed by the isotensor ππ → ππ S-wave scattering, we re-fit the CERN-Munich (CM) data on ππ scattering to get parameters for the f0(X). We find that the f0(X) is very broad with a nearby pole at (1.67−0.26i) GeV, while the t-channel ρ meson exchange part produces a pole at (0.36− 0.53i) GeV. The implication of our results for the study of σ and glueball is discussed. PACS number(s): 14.40Cs, 11.80.Gw, 13.75.Lb Supported in part by National Natural Science Foundation of China under Grant Nos.19775051 19875024 and 19905011 Email: [email protected], [email protected], [email protected] Mailing address
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