Data di Pubblicazione:
2010
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.
Tipologia CRIS:
03A-Articolo su Rivista
Keywords:
Virtual bremsstrahlung; Dileptons; Nucleon–nucleon collisions
Elenco autori:
G. Agakichiev; A. Balanda; D. Belver; A.V. Belyaev; A. Blanco; M. Böhmer; J.L. Boyard; P. Braun-Munzinger; P. Cabanelas; E. Castro; S. Chernenko; T. Christ; M. Destefanis; J. Díaz;
F. Dohrmann; A. Dybczak; L. Fabbietti; O.V. Fateev; P. Finocchiaro; P. Fonte; J. Friese; I. Fröhlich; T. Galatyuk; J.A. Garzón; R. Gernhäuser; A. Gil; C. Gilardi; K. Göbel; M. Golubeva;
D. González-Díaz; F. Guber; T. Hennino; R. Holzmann; I. Iori; A. Ivashkin; M. Jurkovic; B. Kämpfer; T. Karavicheva; D. Kirschner; I. Koenig; W. Koenig; B.W. Kolb; R. Kotte; F. Krizek;
R. Krücken; W. Kühn; A. Kugler; A. Kurepin; 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; Yu.G. Sobolev; S. Spataro; B. Spruck;H. Ströbele; J. Stroth; C. Sturm; M. Sudol; A. Tarantola; K. Teilab; P. Tlusty; M. Traxler;R. Trebacz; H. Tsertos; V. Wagner; M. Weber; M. Wisniowski; T. Wojcik; J. Wüstenfeld;S. Yurevich; Y.V. Zanevsky; P. Zhou
Link alla scheda completa:
Pubblicato in: