Inclusive dielectron spectra in p+p collisions at 3.5 GeV kinetic beam energy

  • HADES Collaboration
  • G. Agakishiev
  • A. Balanda
  • D. Belver
  • A. Belyaev
  • A. Blanco
  • M. Böhmer
  • J. L. Boyard
  • P. Cabanelas
  • E. Castro
  • J. C. Chen
  • S. Chernenko
  • T. Christ
  • M. Destefanis
  • F. Dohrmann
  • A. Dybczak
  • E. Epple
  • L. Fabbietti
  • O. Fateev
  • P. Finocchiaro
  • P. Fonte
  • J. Friese
  • I. Fröhlich
  • T. Galatyuk
  • J. A. Garzón
  • R. Gernhäuser
  • C. Gilardi
  • M. Golubeva
  • D. González-Díaz
  • F. Guber
  • M. Gumberidze
  • T. Heinz
  • T. Hennino
  • R. Holzmann
  • A. Ierusalimov
  • I. Iori
  • A. Ivashkin
  • M. Jurkovic
  • B. Kämpfer
  • K. Kanaki
  • T. Karavicheva
  • I. Koenig
  • W. Koenig
  • B. W. Kolb
  • R. Kotte
  • A. Krása
  • F. Krizek
  • R. Krücken
  • H. Kuc
  • W. Kühn
  • A. Kugler
  • A. Kurepin
  • R. Lalik
  • S. Lang
  • J. S. Lange
  • K. Lapidus
  • T. Liu
  • L. Lopes
  • M. Lorenz
  • L. Maier
  • A. Mangiarotti
  • J. Markert
  • V. Metag
  • B. Michalska
  • J. Michel
  • E. Morinière
  • J. Mousa
  • C. Müntz
  • L. Naumann
  • J. Otwinowski
  • Y. C. Pachmayer
  • M. Palka
  • Y. Parpottas
  • V. Pechenov
  • O. Pechenova
  • J. Pietraszko
  • W. Przygoda
  • B. Ramstein
  • A. Reshetin
  • A. Rustamov
  • A. Sadovsky
  • P. Salabura
  • A. Schmah
  • E. Schwab
  • J. Siebenson
  • Yu. G. Sobolev
  • S. Spataro
  • B. Spruck
  • H. Ströbele
  • J. Stroth
  • C. Sturm
  • A. Tarantola
  • K. Teilab
  • P. Tlusty
  • M. Traxler
  • R. Trebacz
  • H. Tsertos
  • V. Wagner
  • M. Weber
  • C. Wendisch
  • J. Wüstenfeld
  • S. Yurevich
  • Y. Zanevsky
Open Access
Regular Article - Experimental Physics

Abstract

We present the inclusive invariant mass, transverse momentum and rapidity distributions of dielectrons (e+e- pairs) in p+p interactions at 3.5GeV beam kinetic energy. In the vector meson mass region, a distinct peak corresponding to direct ω decays is reconstructed with a 2% mass resolution. The data is compared to predictions from three model calculations. Due to the large acceptance of the HADES apparatus for e+e- invariant masses above 0.2 GeV/c2 and for transverse pair momenta pt < 1 GeV/c, acceptance corrections are, to a large extent, model independent. This allows us to extract from dielectron data for the first time at this energy the inclusive production cross-sections for light vector mesons. Inclusive production cross-sections for π0 and η mesons are also reported. The obtained results will serve as an important reference for the study of vector meson production in proton-nucleus and heavy-ion collisions. Furthermore, using this data, an improved value for the upper bound of the branching ratio for direct η decays into the electron-positron channel is obtained.

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Copyright information

© The Author(s) 2012

Authors and Affiliations

  • HADES Collaboration
  • G. Agakishiev
    • 6
  • A. Balanda
    • 3
  • D. Belver
    • 17
  • A. Belyaev
    • 6
  • A. Blanco
    • 2
  • M. Böhmer
    • 9
  • J. L. Boyard
    • 15
  • P. Cabanelas
    • 17
  • E. Castro
    • 17
  • J. C. Chen
    • 8
  • S. Chernenko
    • 6
  • T. Christ
    • 9
  • M. Destefanis
    • 10
  • F. Dohrmann
    • 5
  • A. Dybczak
    • 3
  • E. Epple
    • 8
  • L. Fabbietti
    • 8
  • O. Fateev
    • 6
  • P. Finocchiaro
    • 1
  • P. Fonte
    • 2
  • J. Friese
    • 9
  • I. Fröhlich
    • 7
  • T. Galatyuk
    • 7
  • J. A. Garzón
    • 17
  • R. Gernhäuser
    • 9
  • C. Gilardi
    • 10
  • M. Golubeva
    • 12
  • D. González-Díaz
    • 1
  • F. Guber
    • 12
  • M. Gumberidze
    • 15
  • T. Heinz
    • 4
  • T. Hennino
    • 15
  • R. Holzmann
    • 4
  • A. Ierusalimov
    • 6
  • I. Iori
    • 11
  • A. Ivashkin
    • 12
  • M. Jurkovic
    • 9
  • B. Kämpfer
    • 5
  • K. Kanaki
    • 5
  • T. Karavicheva
    • 12
  • I. Koenig
    • 4
  • W. Koenig
    • 4
  • B. W. Kolb
    • 4
  • R. Kotte
    • 5
  • A. Krása
    • 16
  • F. Krizek
    • 16
  • R. Krücken
    • 9
  • H. Kuc
    • 3
    • 15
  • W. Kühn
    • 10
  • A. Kugler
    • 16
  • A. Kurepin
    • 12
  • R. Lalik
    • 8
  • S. Lang
    • 4
  • J. S. Lange
    • 10
  • K. Lapidus
    • 8
  • T. Liu
    • 15
  • L. Lopes
    • 2
  • M. Lorenz
    • 7
  • L. Maier
    • 9
  • A. Mangiarotti
    • 2
  • J. Markert
    • 7
  • V. Metag
    • 10
  • B. Michalska
    • 3
  • J. Michel
    • 7
  • E. Morinière
    • 15
  • J. Mousa
    • 14
  • C. Müntz
    • 7
  • L. Naumann
    • 5
  • J. Otwinowski
    • 3
  • Y. C. Pachmayer
    • 7
  • M. Palka
    • 7
  • Y. Parpottas
    • 14
    • 13
  • V. Pechenov
    • 4
  • O. Pechenova
    • 7
  • J. Pietraszko
    • 7
  • W. Przygoda
    • 3
  • B. Ramstein
    • 15
  • A. Reshetin
    • 12
  • A. Rustamov
    • 7
  • A. Sadovsky
    • 12
  • P. Salabura
    • 3
  • A. Schmah
    • 1
  • E. Schwab
    • 4
  • J. Siebenson
    • 8
  • Yu. G. Sobolev
    • 16
  • S. Spataro
    • 1
  • B. Spruck
    • 10
  • H. Ströbele
    • 7
  • J. Stroth
    • 7
    • 4
  • C. Sturm
    • 4
  • A. Tarantola
    • 7
  • K. Teilab
    • 7
  • P. Tlusty
    • 16
  • M. Traxler
    • 4
  • R. Trebacz
    • 3
  • H. Tsertos
    • 14
  • V. Wagner
    • 16
  • M. Weber
    • 9
  • C. Wendisch
    • 5
  • J. Wüstenfeld
    • 5
  • S. Yurevich
    • 4
  • Y. Zanevsky
    • 6
  1. 1.Istituto Nazionale di Fisica NucleareLaboratori Nazionali del SudCataniaItaly
  2. 2.LIP-Laboratório de Instrumentação e Física Experimental de PartículasCoimbraPortugal
  3. 3.Smoluchowski Institute of PhysicsJagiellonian University of CracowKrakówPoland
  4. 4.GSI Helmholtzzentrum für Schwerionenforschung GmbHDarmstadtGermany
  5. 5.Institut für StrahlenphysikHelmholtz-Zentrum Dresden-RossendorfDresdenGermany
  6. 6.Joint Institute of Nuclear ResearchDubnaRussia
  7. 7.Institut für KernphysikGoethe-UniversitätFrankfurtGermany
  8. 8.Excellence Cluster “Origin and Structure of the Universe”GarchingGermany
  9. 9.Physik Department E12Technische Universität MünchenGarchingGermany
  10. 10.II.Physikalisches InstitutJustus Liebig Universität GiessenGiessenGermany
  11. 11.Istituto Nazionale di Fisica Nucleare, Sezione di MilanoMilanoItaly
  12. 12.Institute for Nuclear ResearchRussian Academy of ScienceMoscowRussia
  13. 13.Frederick UniversityNicosiaCyprus
  14. 14.Department of PhysicsUniversity of CyprusNicosiaCyprus
  15. 15.Institut de Physique Nucléaire (UMR 8608), CNRS/IN2P3Université Paris SudOrsay CedexFrance
  16. 16.Nuclear Physics InstituteAcademy of Sciences of Czech RepublicRezCzech Republic
  17. 17.Departamento de Física de PartículasUniv. de Santiago de CompostelaSantiago de CompostelaSpain

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