Speaker
Frank Geurts
(Rice University (US))
Description
Dileptons in the low mass region, ($M_{ll} < 1.1 {\rm GeVc}^{-2}$), retain
information about vector mesons that originated in the strongly
interacting matter created by relativistic heavy-ion collisions.
Linking these vector mesons to an in-medium broadening of their spectral
functions may suggest chiral symmetry restoration[1]. Measurements at SPS
and RHIC energies have been made in the low mass region that are
consistent with in-medium modification of the $\rho$ meson spectral
function. By using RHIC's beam energy scan (BES) program and its
high-purity, large-acceptance electron identification, STAR has been
systematically studying the production of low mass dielectrons as a
function of collision energy. We present the preliminary results of the
low mass dielectron production in Au+Au collisions at $\sqrt{s_{NN}}$ = 27
GeV. The study is focused on the comparison of the spectra with the
expected hadronic contributions and with models that include production
from $\rho$ with an in-medium modified spectral function and medium
radiation. In addition, the results will be compared with previously
presented measurements from other BES energies ($\sqrt{s_{NN}}$ = 19.6,
39, and 62.4 GeV) and projections for future BES-2 measurements will be presented.
[1] R.Rapp and J.Wambach, Advances in Nuclear Physics 25(2000).
| On behalf of collaboration: | STAR |
|---|
Authors
Frank Geurts
(Rice University (US))
Joey Butterworth
(Rice University)
