Measurement of high-p_T Single Electrons from Heavy-Flavor Decays in p+p Collisions at sqrt(s) = 200 GeV

TL;DR

Two independent methods have been used to determine the heavy-flavor yields, and the results are in good agreement with each other.

Abstract

The momentum distribution of electrons from decays of heavy flavor (charm and beauty) for midrapidity |y| < 0.35 in p+p collisions at sqrt(s) = 200 GeV has been measured by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) over the transverse momentum range 0.3 < p_T < 9 GeV/c. Two independent methods have been used to determine the heavy flavor yields, and the results are in good agreement with each other. A fixed-order-plus-next-to-leading-log pQCD calculation agrees with the data within the theoretical and experimental uncertainties, with the data/theory ratio of 1.72 +/- 0.02^stat +/- 0.19^sys for 0.3 < p_T < 9 GeV/c. The total charm production cross section at this energy has also been deduced to be sigma_(c c^bar) = 567 +/- 57^stat +/- 224^sys micro barns.

Figures (3)

• Figure 1: Ratio of photonic electrons measured by the converter method to the cocktail calculation. Data from the MB (PH) dataset are shown below (above) 1.8 GeV/$c$. The upper and lower curves show the systematic error of the cocktail. Error bars are statistical only.
• Figure 2: Ratio of non-photonic electrons to photonic background. Error bars are statistical errors and the error bands show the cocktail systematic errors. The solid, dashed, dot-dashed, and dot curve is the remaining non-photonic background from $K_{e3}$, $\rho \rightarrow ee$, $\omega \rightarrow ee$, and hadron contamination, respectively.
• Figure 3: (a) Invariant differential cross sections of electrons from heavy-flavor decays. The error bars (bands) represent the statistical (systematic) errors. The curves are the FONLL calculations (see text). (b) Ratio of the data and the FONLL calculation. The upper (lower) curve shows the theoretical upper (lower) limit of the FONLL calculation. In both panels a 10% normalization uncertainty is not shown.