skip to main content

DOE PAGESDOE PAGES

Title: Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au+Au collisions √sNN = 19.6 and 200 GeV

The acceptance-corrected dielectron excess mass spectra, where the known hadronic sources have been subtracted from the inclusive dielectron mass spectra, are reported for the first time at mid-rapidity |yee| < 1 in minimum-bias Au+Au collisions at √sNN = 19.6 and 200 GeV. The excess mass spectra are consistently described by a model calculation with a broadened ρ spectral function for Mee < 1.1 GeV/c2. The integrated dielectron excess yield at √sNN = 19.6 GeV for 0.4 < Mee < 0.75 GeV/c2, normalized to the charged particle multiplicity at mid-rapidity, has a value similar to that in In + In collisions at √sNN = 17.3 GeV. For √sNN = 200 GeV, the normalized excess yield in central collisions is higher than that at √sNN = 17.3 GeV and increases from peripheral to central collisions. The measurements indicate that the lifetime of the hot, dense medium created in central Au + Au collisions at √sNN = 200 GeV is longer than those in peripheral collisions and at lower energies.
Authors:
 [1]
  1. AGH Univ. of Science and Technology, Cracow (Poland) et al.
Publication Date:
Report Number(s):
BNL-108359-2015-JA
Journal ID: ISSN 0370-2693; R&D Project: PO 004; KB0202012
Grant/Contract Number:
NRF-2012004024
Type:
Published Article
Journal Name:
Physics Letters. Section B
Additional Journal Information:
Journal Volume: 750; Journal Issue: C; Journal ID: ISSN 0370-2693
Publisher:
Elsevier
Research Org:
Brookhaven National Lab. (BNL), Upton, NY (United States). Relativistic Heavy Ion Collider (RHIC)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26); USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Relativistic Heavy Ion Collider
OSTI Identifier:
1213885
Alternate Identifier(s):
OSTI ID: 1221752