We investigate the $\mathit{pp}\to \mathit{pp}\eta$ and $\mathit{pn}\to \mathit{pn}\eta$ reactions within an effective Lagrangian model for laboratory kinetic energies ranging from very close to the η-meson production threshold to about 10 GeV. Production amplitudes include contributions from the mechanisms of excitation, propagation, and decay of $N^{*}(1535),N^{*}(1650)$, and $N^{*}(1710)$ baryonic resonances. The initial interaction between two incoming nucleons is modeled by the exchange of $\pi ,\rho ,\omega ,$ and σ mesons where the vertex parameters are taken to be the same as those used in the previous applications of this model. Parameters of the resonance vertices also are taken from our earlier studies wherever applicable. Calculations are done for total as well as differential η-production cross sections. To describe the data for energies closer to the production threshold, final state interactions among the outgoing particles are included by means of a generalized Watson-Migdal method. Terms corresponding to the excitation of $N^{*}$(1535) resonance and the pion exchange process dominate the cross sections. With a single set of vertex parameters, our model describes well the available data on total cross sections for beam energies ranging from close to threshold to up to 10 GeV.

• Received 22 December 2006

DOI:https://doi.org/10.1103/PhysRevC.75.055201