2008/05/01 by Alberica Toia
Earth and Planetary Sciences · Physics and Astronomy · #Dust and Plasma Wave Phenomena #Earth Systems and Cosmic Evolution #High-Energy Particle Collisions Research #nucl-ex
paper · pdf · doi:10.1088/0954-3899/35/10/104037
published as J.Phys.G35:104037,2008 · Proceedings of Quark Matter 2008, 8 pages, 7 figures
arxiv created 2008/05/01 · openalex publication_date 2008/09/17 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
Recently, there has been growing evidence that a new state of matter is formed in GeV Au+Au collisions at RHIC: a strongly coupled quark–gluon plasma of partonic degrees of freedom which develops a collective motion. Dileptons are not affected by the strong interaction and can therefore probe the whole time evolution of the collision. Thus they may be sensitive to the onset of deconfinement, chiral symmetry restoration, as well as the production of thermal photons via their internal conversion. The PHENIX experiment measured the production of e + e − pairs in p+p and Au+Au collisions at GeV. An enhanced dilepton yield in the mass range 150 < m ee < 750 MeV/ c 2 was measured. The excess increases faster with centrality than the number of participating nucleons and is concentrated at p T < 1 GeV/ c . At higher p T the excess below 300 MeV/c 2 in mass has been related to an enhanced production of direct photons, possibly of thermal origin.