$\chi$PT Calculations with two-pion Loops for S-wave ${\pi }^0$ Production in pp Collision

Abstract

The total cross section for the $pp\to pp{\pi }^0$ reaction at energies close to threshold is calculated within the frame of a chiral perturbation theory, taking into account tree and one loop diagrams up to chiral order D=2. Two-pion loop contributions dominate ${\pi }^0$ production at threshold. The calculated cross section reproduces data, both scale and energy dependence, fairly well.

Comments: REVTeX, graphicx, 12 pages (including 4 figures)