Padé Unitarizations: A Critical Look
نویسنده
چکیده
One of the most interesting aspects of strong interactions is the enormously rich and complicated hadronic spectrum that arises from such a simple high energy structure. How does exactly this spectrum arise from QCD is a question under study. The understanding of QCD at low energies is basically provided by ChPT [1], the low energy effective theory of QCD, which gives also some insight on the spectrum issue. Although ChPT breaks down in the vicinity of the resonance region, arguments following from unitarity and analyticity are able to extract information on some resonances from the chiral Lagrangian, which contains such information hidden in the values of its low energy constants. One of the most successful of such unitarization procedures is the Inverse Amplitude Method (IAM) [2], which is able to extract with acceptable accuracy the lowest lying scalar and vector resonances. These proceedings are based on the work of Ref. [3], where some of the unitarization techniques are tested by means of the Linear Sigma Model, for which exact information about the sigma resonance is available. We focus on the IAM and also on some sequences of Padé Approximants (PAs) [4].
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تاریخ انتشار 2008