Dielectron production in Ar+KCl collisions at 1.76A GeV
Abstract
We present results on dielectron production in Ar+KCl collisions at 1.76A GeV. For the first time mesons could be reconstructed in a heavy-ion reaction at a bombarding energy which is well below the production threshold in free nucleon-nucleon collisions. The omega multiplicity has been extracted and compared to the yields of other particles, in particular of the phi meson. At intermediate e+e- invariant masses, we find a strong enhancement of the pair yield over a reference spectrum from elementary nucleon-nucleon reactions suggesting the onset of non-trivial effects of the nuclear medium. Transverse-mass spectra and angular distributions have been reconstructed in three invariant mass bins. In the former unexpectedly large slopes are found for high-mass pairs. The latter, in particular the helicity-angle distributions, are largely consistent with expectations for a pair cocktail dominated at intermediate masses by delta Dalitz decays.
Keywords
Cite
@article{arxiv.1103.0876,
title = {Dielectron production in Ar+KCl collisions at 1.76A GeV},
author = {G. Agakishiev and A. Balanda and D. Belver and A. Belyaev and A. Blanco and M. Böhmer and J. L. Boyard and P. Cabanelas and E. Castro and S. Chernenko and T. Christ and M. Destefanis and F. Dohrmann and A. Dybczak and T. Eberl and E. Epple and L. Fabbbietti and O. Fateev and P. Finocchiaro and P. Fonte and J. Friese and I. Fröhlich and T. Galatyuk and J. A. Garzon and R. Gernhäuser and C. Gilardi and M. Golubeva and D. Gonzalez-Díaz and F. Guber and M. Gumberidze and T. Heinz and T. Hennino and R. Holzmann and P. Huck and I. Iori and A. Ivashkin and M. Jurkovic and B. Kämpfer and K. Kanaki and T. Karavicheva and I. Koenig and W. Koenig and B. W. Kolb and R. Kotte and A. Krasa and F. Krizek and R. Krücken and H. Kuc and W. Kühn and A. Kugler and A. Kurepin and S. Lang and J. S. Lange and K. Lapidus T. Liu and L. Lopes and M. Lorenz and L. Maier and A. Mangiarotti and J. Markert and V. Metag and B. Michalska and J. Michel and E. Moriniere and J. Mousa and C. Müntz and L. Naumann and J. Otwinowski and Y. C. Pachmayer and M. Palka and V. Pechenov and O. Pechenova and J. Pietraszko and W. Przygoda and B. Ramstein and A. Reshetin and A. Rustamov and A. Sadovsky and B. Sailer and P. Salabura and A. Schmah and E. Schwab and J. Siebenson and Yu. G. Sobolev and S. Spataro and B. Spruck and H. Ströbele and J. Stroth and C. Sturm and A. Tarantola and K. Teilab and P. Tlusty and M. Traxler and R. Trebacz and H. Tsertos and V. Wagner and M. Weber and C. Wendisch and M. Wisniowski and J. Wüstenfeld and S. Yurevich and Y. Zanevsky},
journal= {arXiv preprint arXiv:1103.0876},
year = {2011}
}
Comments
16 pages, 14 figures, accepted for publication by Phys. Rev. C