TU Darmstadt / ULB / TUbiblio

Analysis of the exclusive final state npe⁺e⁻ in quasi-free np reaction

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
Export:
Suche nach Titel in: TUfind oder in Google
Send an inquiry Send an inquiry

Options (only for editors)
Show editorial Details Show editorial Details