Speaker
Dr
Richard Petti
(Brookhaven National Lab)
Description
Photons are unmodified once produced in heavy ion collisions, so
they provide information about the entire thermal evolution of the
medium. PHENIX measured photon yields exceeding that expected
from initial hard scattering and observed a large azimuthal
anisotropy, $v_2$, of these soft photons with respect to the
reaction plane. The large yield and $v_2$
continue to challenge simultaneous quantitative descriptions and
raise important questions about the early time dynamics in the
medium. More differential measurements provide information to help
distinguish various potential explanations for this thermal photon
puzzle. We present yields of direct photons from Au$+$Au collisions
at $\sqrt{s_{NN}}$=62.4 GeV and the yield, $v_2$, and $v_3$ from
Au$+$Au collisions at $\sqrt{s_{NN}}$=200 GeV.
| On behalf of collaboration: | PHENIX |
|---|
Primary author
Dr
Richard Petti
(Brookhaven National Lab)
