Measurement of High-$p_T$ Single Electrons from Heavy-Flavor Decays in $p+p$ Collisions at $\sqrt{s}=200\mathrm{GeV}$

The momentum distribution of electrons from decays of heavy flavor (charm and bottom) for midrapidity $|y|<0.35$ in $p+p$ collisions at $\sqrt{s}=200\mathrm{GeV}$ has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over the transverse momentum range $0.3<p_T<9\mathrm{GeV}/c$. 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 perturbative QCD calculation agrees with the data within the theoretical and experimental uncertainties, with the data/theory ratio of $1.71\pm {0.02}^{\mathrm{stat}}\pm {0.18}^{\mathrm{sys}}$ for $0.3<p_T<9\mathrm{GeV}/c$. The total charm production cross section at this energy has also been deduced to be ${\sigma }_{c\overline{c}}=567\pm {57}^{\mathrm{stat}}\pm {193}^{\mathrm{sys}}\mu \mathrm{b}$.

Figure 1

Ratio of photonic electrons measured by the converter method to the cocktail calculation. Data from the MB (PH) data set are shown below (above) $1.8\mathrm{GeV}/c$. The upper and lower curves show the systematic error of the cocktail. Error bars are statistical only.

Figure 2

Ratio of nonphotonic 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 are the remaining nonphotonic backgrounds from $K_{e3}$, $\rho \to ee$, $\omega \to ee$, 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.