Measurement of bottom versus charm as a function of transverse momentum with electron-hadron correlations in p+p Collisions at s=200GeV

Abstract

The momentum distribution of electrons from semileptonic decays of charm and bottom quarks for midrapidity |y|<0.35 in p+p collisions at s=200GeV is measured by the PHENIX experiment at the Relativistic Heavy Ion Collider over the transverse momentum range 2<pT<7GeV/c. The ratio of the yield of electrons from bottom to that from charm is presented. The ratio is determined using partial D/D̄→e±K X (K unidentified) reconstruction. It is found that the yield of electrons from bottom becomes significant above 4GeV/c in pT. A fixed-order-plus-next-to-leading-log perturbative quantum chromodynamics calculation agrees with the data within the theoretical and experimental uncertainties. The extracted total bottom production cross section at this energy is σbb̄=3.2-1.1+1.2(stat)-1.3+1.4(syst)μb. © 2009 The American Physical Society.