Skip to Main content Skip to Navigation
Journal articles

Origin of the low-mass electron pair excess in light nucleus-nucleus collisions

Abstract : We report measurements of electron pair production in elementary p+p and d+p reactions at 1.25 GeV/u with the HADES spectrometer. For the first time, the electron pairs were reconstructed for n+p reactions by detecting the proton spectator from the deuteron breakup. We find that the yield of electron pairs with invariant mass Me+e- > 0.15 GeV/c2 is about an order of magnitude larger in n+p reactions as compared to p+p. A comparison to model calculations demonstrates that the production mechanism is not sufficiently described yet. The electron pair spectra measured in C+C reactions are compatible with a superposition of elementary n+p and p+p collisions, leaving little room for additional electron pair sources in such light collision systems.
Document type :
Journal articles
Complete list of metadatas

http://hal.in2p3.fr/in2p3-00429566
Contributor : Sophie Heurteau <>
Submitted on : Tuesday, November 3, 2009 - 2:56:15 PM
Last modification on : Wednesday, September 16, 2020 - 4:07:55 PM

Links full text

Identifiers

Collections

Citation

G. Agakishiev, A. Balanda, D. Belver, A. V. Belyaev, A. Blanco, et al.. Origin of the low-mass electron pair excess in light nucleus-nucleus collisions. Physics Letters B, Elsevier, 2010, 690, pp.118-122. ⟨10.1016/j.physletb.2010.05.010⟩. ⟨in2p3-00429566⟩

Share

Metrics