Pi pi -Scattering Lengths

摘要

The a sub 00 , a sub 02 , a sub 11 , a sub 20 , a sub 22 , and a sub 31 pi pi scattering lengths are calculated in the framework of the composite meson model which is based on four-quark interactions. The decay form factors of rho yields 2 pi and epsilon yields 2 pi are used. The q exp 2 -terms of the quark box diagrams are taken into account. The values for a sub 20 and a sub 22 are close to each other. The a sub 00 and a sub 11 scattering lengths differ from Weinberg theoretical estimations. The a sub 02 scattering length corresponds to Weinberg data. (Atomindex citation 15:020019)