Psi prime to J/psi Ratio Measurements in PHENIX at RHIC

Abstract

The ratio of the $\psi'$ over the $J/\psi$ production cross section in the dielectron channel has been measured in $\sqrt{s}=$ 200 GeV $p+p$ collisions with the PHENIX detector at RHIC. The analysis is based on fitting of the dielectron invariant mass spectra in the area around the $J/\psi$ and $\psi'$ signals in order to extract a ratio $\psi'$ over $J/\psi$ of 0.019$\pm 0.005($stat$)\pm 0.002($sys$)$ and a fractional feed-down contribution to $J/\psi$ from $\psi^\prime$ of $8.6 \pm 2.5 %$.