Dispersion sum rules for pion polarizabilities

Abstract

An analysis of different dispersion sum rules (DSRs) for the dipole and quadrupole pion polarizabilities is carried out. We prove the absence of additional spurious singularities in these approaches. The results of the calculations of the polarizabilities in the framework of DSRs are compared with ChPT predictions and with data obtained in different experiments.

Comments: 9 pages, to appear in the 6th International Workshop on Chiral Dynamics, CD09, July 6-10, 2009, Bern, Switzerland; minor changes