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.
Original language | English |
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Article number | 64 |
Pages (from-to) | 1-11 |
Number of pages | 11 |
Journal | European Physical Journal A |
Volume | 48 |
Issue number | 5 |
DOIs | |
State | Published - 2012 |
Externally published | Yes |