Role of the Δ-isobar excitation mechanism in the reaction pp → {pp}sπ0

Abstract

The mechanism of Δ-isobar excitation in the intermediate state of the reaction pp → {pp}_sπ⁰, where {pp}_s is a pair of protons in state ¹S₀ at excitation energy E_pp < 3 MeV, is used to calculate the differential cross section of this reaction in the energy range of 0.3–1 GeV. It is shown that the main contribution is made by three partial waves in the pp channel: ³P₀, ³P₂ and ³F₂. The model explains the position of the peak observed at a beam energy of GeV and a zero diproton scattering angle, but cannot describe its absolute value.