Abstract: Non-photonic electron production in Cu+Cu and Au+Au collisions at GeV at STAR.
High-energy nucleus-nucleus collisions at RHIC allow the study of the behavior of nuclear matter at high
temperatures, where a new phase of matter, the quark-gluon plasma is predicted to exist. All partons
are thought to lose energy through gluon radiation as they pass through the hot and dense
nuclear matter; however heavy quarks are expected to lose less energy than light quarks and gluons
due to the suppression of small-angle gluon radiation. Non-photonic electrons (proxies for heavy quarks) are suppressed
by a factor of ~5 in central Au+Au collisions relative to $p+p$ collisions at GeV.
This suppression is larger than most current theoretical predictions and has led to a re-examination of
heavy-quark energy loss in the medium.
A measurement of the non-photonic electron spectrum in Cu+Cu collisions at GeV is presented. The
spectrum is compared to the non-photonic electron yields from $p+p$ and Au+Au collisions at the same
energy to extract the nuclear modification factor and the dependence of the non-photonic electron yield on