ed.: HADES Collaboration (2017)
Analysis of the exclusive final state npe⁺e⁻ in quasi-free np reaction.
In: The European Physical Journal A, 53 (7)
doi: 10.1140/epja/i2017-12341-3
Article, Bibliographie
Abstract
We report on the investigation of dielectron production in tagged quasi-free neutron-proton collisions by using a deuteron beam of kinetic energy 1.25 GeV/u impinging on a liquid hydrogen target. Our measurements with HADES confirm a significant excess of e+e− pairs above the π0 mass in the exclusive channel dp → npe+e−(pspect) as compared to the exclusive channel ppe+e− measured in proton-proton collisions at the same energy. That excess points to different bremsstrahlung production mechanisms. Two models were evaluated for the role of the charged pion exchange between nucleons and double-Δ excitation combined with intermediate ρ-meson production. Differential cross sections as a function of the e+e−invariant mass and of the angles of the virtual photon, proton and electrons provide valuable constraints and encourage further investigations on both experimental and theoretical sides.
Item Type: | Article |
---|---|
Erschienen: | 2017 |
Type of entry: | Bibliographie |
Title: | Analysis of the exclusive final state npe⁺e⁻ in quasi-free np reaction |
Language: | English |
Date: | 18 July 2017 |
Publisher: | Springer |
Journal or Publication Title: | The European Physical Journal A |
Volume of the journal: | 53 |
Issue Number: | 7 |
DOI: | 10.1140/epja/i2017-12341-3 |
Abstract: | We report on the investigation of dielectron production in tagged quasi-free neutron-proton collisions by using a deuteron beam of kinetic energy 1.25 GeV/u impinging on a liquid hydrogen target. Our measurements with HADES confirm a significant excess of e+e− pairs above the π0 mass in the exclusive channel dp → npe+e−(pspect) as compared to the exclusive channel ppe+e− measured in proton-proton collisions at the same energy. That excess points to different bremsstrahlung production mechanisms. Two models were evaluated for the role of the charged pion exchange between nucleons and double-Δ excitation combined with intermediate ρ-meson production. Differential cross sections as a function of the e+e−invariant mass and of the angles of the virtual photon, proton and electrons provide valuable constraints and encourage further investigations on both experimental and theoretical sides. |
Additional Information: | Art.No.: 149 |
Divisions: | 05 Department of Physics 05 Department of Physics > Institute of Nuclear Physics 05 Department of Physics > Institute of Nuclear Physics > Experimentelle Kernphysik 05 Department of Physics > Institute of Nuclear Physics > Experimentelle Kernphysik > Untersuchung von Quark-Materie mit virtuellen Photonen |
Date Deposited: | 26 Feb 2024 15:45 |
Last Modified: | 30 Apr 2024 08:43 |
PPN: | 517669773 |
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