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arXiv · 0903.2466

Di-Electrons from Resonances in Nucleon-Nucleon Collisions

L. P. Kaptari·B. Kampfer
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Abstract

The contribution of the low-lying nucleon resonances $P_{33}(1232)$, $P_{11}(1440)$ $D_{13}(1520)$ and $S_{11}(1535)$ to the invariant mass spectra of di-electrons stemming from the exclusive processes $pp\to pp e^+e^-$ and $pn\to pn e^+e^-$ is investigated within a fully covariant and gauge invariant diagrammatical approach. We employ, within the one-boson exchange approximation, effective nucleon-meson interactions including the exchange mesons $π$, $η$, $σ$, $ω$ and $ρ$ as well as excitations and radiative decays of the above low-lying nucleon resonances. The total contribution of these resonances is dominant, however, bremsstrahlung processes in $pp$ and, in particular, $pn$ collisions at beam energies of 1 - 2 GeV are still significant in certain phase space regions.

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L. P. Kaptari, B. Kampfer. 2009-03-13. Di-Electrons from Resonances in Nucleon-Nucleon Collisions. https://doi.org/10.1103/physrevc.80.064003

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