6,046 research outputs found
Meson Mixing and Dilepton Production in Heavy Ion Collisions
We study the possibility of mixing via N-N excitations in dense
nuclear matter. This mixing is found to induce a peak in the dilepton spectra
at an invariant mass equal to that of the . We calculate the cross section
for dilepton production through mixing and we compare its size with that of
annihilation. In-medium masses and mixing angles are also calculated.
Some preliminary results of the mixing effect on the dilepton production rates
at finite temperature are also presented.Comment: To be published in the proceedings of CIPANP 200
A unique parametrization of the shapes of secondary dilepton spectra observed in central heavy-ion collisions at CERN-SPS energies
A unique parametrization of secondary (thermal) dilepton yields in heavy-ion
experiments at CERN-SPS is proposed. This parametrization resembles a thermal
annihilation rate. This is inspired by the observation that lepton
pair production rates are quantitatively similar, whether expressed in a
hadronic or partonic basis. Adding the thermal yield and the background
contributions (hadronic cocktail, Drell-Yan, correlated semileptonic decays of
open charm) the spectral shapes of the CERES/NA45, NA38, NA50 and HELIOS/3 data
from experiments with lead and sulfur beams can be well described.Comment: 23 pages including figures (new version: only new output format
Squeezing lepton pairs out of broken symmetries
We discuss two possible signatures of symmetry breaking that can appear in
dilepton spectra, as measured in relativistic heavy ion collisions. The first
involves scalar-vector meson mixing and is related to the breaking of Lorentz
symmetry by a hot medium. The second is related to the breaking of Furry's
theorem by a charged quark-gluon plasma. Those signals will be accessible to
upcoming measurements to be performed at the GSI, RHIC, and the LHC.Comment: 5 pages, 4 figures, talk given at the INPC 2001 (International
Conference on Nuclear Physics), 30 July - 3 August 2001, Berkeley, C
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