bb-bar Production Cross Section in 920 GeV p-N Collisions

TL;DR

This paper reports a measurement of the b-bbar production cross section in 920 GeV proton-nucleus collisions using the HERA-B detector, identifying events via J/psi decays to muons or electrons, and comparing results with QCD predictions.

Contribution

First measurement of b-bbar production cross section at 920 GeV p-N collisions with improved precision using the HERA-B detector.

Findings

Measured cross section: 32 +14 -12 nb/nucleon.

Results agree with QCD predictions.

Future data will refine the measurement.

Abstract

The b-bbar production cross section in 920 GeV proton - nucleus collisions was obtained with the HERA-B detector, using a sample of 1.35 million of di-lepton triggered events taken during the 2000 physics run. The b-bbar events are identified via the inclusive decay b->J/psi, where the J/Psi mesons decay to mu+mu- or e+e-. The b events are separated from directly produced J/psi's by requiring that the J/psi decay vertex does not coincide with the primary vertex. The total measured cross section per nucleon, combining the results obtained in the two channels, is 32 +14 -12(stat) +6 -7(sys) nb/nucleon. The result is compared with the most recent QCD prediction and other experimental results. A much more precise measurement will be obtained from the 2002/2003 data.