The Inverse Amplitude Method and Heavy Baryon Chiral Perturbation Theory applied to pion-nucleon scattering

We report on our present work, where by means of the Inverse Amplitude Method we unitarize the elastic pion nucleon scattering amplitudes of Heavy Barion Chiral Perturbation Theory at O(q^3). We reproduce the scattering up to the inelastic thresholds including the Delta(1232) resonance. The fitted chiral constants are rather different from those obtained by fitting the extrapolated threshold parameters for the non-unitarized theory.Comment: Talk given at the 8th International Conference on Hadron Spectroscopy, HADRON99, August 24-28, 1999, Beijing, China. 4 pages LaTex, uses espcrc1.sty (included

On the Wess-Zumino-Witten anomalous functional at finite temperature

We discuss the finite temperature extension of the anomalous Wess-Zumino -Witten lagrangian. The finite temperature S^1\times S^3 compactification makes a structure in disconnected sectors, corresponding to different baryon numbers appear naturally. The consistency of the anomalous functional is proved for arbitrary baryon number configurations. The anomalous behavior of the functional is shown to be consistent with the absence of finite temperature corrections to chiral anomalies in QCD, for each baryon number sector.Comment: 16 pages, FT/UCM/9/9