Speaker
Chi Yang
(USTC/BNL)
Description
One important physics goal of ultra-relativistic heavy-ion collisions is
to study the fundamental properties of a hot, dense medium created in these collisions.
This medium is expected to emit thermal radiation which is in the
form of direct photons and dileptons. Once produced, photons and leptons
traverse the strongly interacting medium with minimal interactions.
The fully installed Time-of-Flight Detector in 2010 enables clean electron
identification from low to intermediate transverse momentum ($p_{T}$). In this
talk, we will present the direct virtual photon production for 1<$p_{T}$<5 GeV/$c$
derived from the dielectron continuum in the dielectron invariant mass region 0.1<$M_{ee}$<0.3 GeV/$c^{2}$
from one billion $\sqrt{s_{NN}}$ = 200 GeV Au+Au minimum bias events taken in 2010 and 2011.
In addition, we will present the centrality and $p_{T}$ dependence of dielectron production
and the dielectron azimuthal angle correlation in the intermediate mass(1.1<$M_{ee}$<3 GeV/$c^{2}$) region in this dataset.
The relevant results from $\sqrt{s}$ = 200 GeV p+p collisions taken in 2012 will also be discussed.
Comparisons to model calculations including hadronic and partonic thermal radiation will be made for
both the direct virtual photon and dielectron production in Au+Au collisions.
| On behalf of collaboration: | STAR |
|---|
Author
Chi Yang
(USTC/BNL)
