S-wave ${\pi }^0$ Production in pp Collision in a Covariant OBE Model

Abstract

The total cross section for the pp -> pp pi^0 reaction at energies close to threshold is calculated using a covariant one-boson-exchange model, where a boson B created on one of the incoming protons is converted into a neutral pion on the second. The amplitudes for the conversion processes, B N -> N pi^0, are taken to be the sum of s, u and t-channel pole terms. The main contributions to the primary production amplitude is due to an effective isoscalar sigma meson pole in a t-channel, which is enhanced strongly due to offshellness. With this contribution included the model reproduces, both the scale and energy dependence of the cross section.

REVTeX, graphicx, 22 pages (icluding 10 figures)

References in corpus (2)

• Chiral Perturbation Theory and the pp -> pp pi0 Reaction Near Threshold
• A Covariant OBE Model for $\eta$ Production in NN Collisions