Speaker
Description
In this poster, PHENIX presents a proof of principle study for the measurement of prompt and non-prompt $e^{+}e^{-}$ pair production in the intermediate mass range ($m_{\phi}$ $<$ $m_{ee}$ $<$ $m_{J/\psi}$) using $p$+$p$ data at 200 GeV taken in 2015. PHENIX plans to extend the measurement to the high statistics Au+Au data-set recorded in 2014 and 2016, with the goal to isolate the expected prompt thermal contribution in the intermediate mass region from non-prompt pairs from heavy flavor decays. In $p$+$p$ collisions the main physics signal in this mass region originates from semileptonic decays of charm and bottom $q\bar{q}$ pairs. The $e^+$ and $e^-$ origin from decays many micron away from the interaction point. This non-prompt component is identified statistically by measuring the distance of closest approach (DCA) with the PHENIX silicon vertex detector (VTX). The VTX has four layers with a total radiation length of about 15\%, thus electrons from photon conversions cause a significant combinatorial background for the measurement, even in $p$+$p$ collisions. We have developed rejection techniques that effectively eliminate this background, improving the signal-to-background ratio by orders of magnitude. We will present the $e^{+}e^{-}$ pair spectra from $p$+$p$ collisions and its non-prompt contributions.
| Category | Experiment |
|---|---|
| Collaboration (if applicable) | PHENIX |
