LATTICE INVESTIGATION OF THE DAS-MATHUR-OKUBO SUM-RULE

An evaluation of charged pion polarizability using correlation functio ns measured on a 16(3) x 24 lattice in the context of the Das-Mathur-O kubo sum rule is carried out. The calculation is Limited to the so-cal led intrinsic part of the polarizability. This contribution, equivalen t to a Euclidean time integral over vector and axial vector momentum-d ifferentiated propagators, is evaluated in both a continuous and discr ete sense. In the continuous case, the time behavior of the correlatio n functions is fit to the continuum quark model; the discrete case is handled by a straightforward application of Simpson's rule for integra tion after subtracting the pion contributions. A comparison of the imp lied vector meson and pion decay constants with phenomenological value s is carried out. Results for the intrinsic polarizability are extrapo lated across four quark mass values to the chiral limit. An extensive discussion of the lattice systematics in this calculation is given.