Abstrakt
The cross section of bottom quark-antiquark (b (b) over bar) production in p + p collisions at root s = 510 GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider. The results are based on the yield of high mass, like-sign muon pairs measured within the PHENIX muon arm acceptance (1.2 mu +/-mu +/-)/dy = 0.16 +/- 0.01 (stat) +/- 0.02 (syst) +/- 0.02 (global) nb for like-sign muons in the rapidity and p(T) ranges 1.2 1 GeV/c, and dimuon mass of 5-10 GeV/c(2).
The extrapolated total cross section at this energy for b (b) over bar production is 13.1 +/- 0.6 (stat) +/- 1.5 (syst) +/- 2.7 (global) mu b. The total cross section is compared to a perturbative quantum chromodynamics calculation and is consistent within uncertainties.
The azimuthal opening angle between muon pairs from b (b) over bar decays and their p(T) distributions are compared to distributions generated using PS PYTHIA6, which includes next-to-leading order processes. The azimuthal correlations and pair p(T) distribution are not very well described by PYTHIA calculations, but are still consistent within uncertainties.
Flavor creation and flavor excitation subprocesses are favored over gluon splitting.