A unitarity analysis on the I=0 d wave ππ scattering amplitude

الأصل · EN

We study I=0 d wave ππ scattering phase shift using a proper unitarization approach. It is verified that the f₂(1270) resonance corresponds to a twin pole structure: one on the second sheet, another one on the third sheet. Also we find fair agreement on f₂(1270) pole's mass and width between our results and the PDG values. Besides, our analysis reveals the existence of a virtual state in this channel. Its pole location is determined by fitting experimental data and it is found to be in good agreement with the prediction from chiral perturbation theory. Our analysis demonstrates that partial wave amplitudes calculated in chiral perturbation theory are reliable in the small |s| region, contrary to some unitarization models.