Measurement of Open Beauty Production at HERA

TL;DR

This paper reports the first measurement of open beauty (b quark) production in ep collisions at HERA, comparing experimental results with QCD predictions and providing cross sections for different production processes.

Contribution

It presents the first observation and measurement of open b production in ep collisions, with detailed cross section results and comparison to NLO QCD calculations.

Findings

Measured visible cross section for b production is 0.176 nb.

Observed cross sections are consistent with QCD predictions within uncertainties.

Provides cross sections for electroproduction and photoproduction at HERA energies.

Abstract

The first observation of open b production in ep collisions is reported. An event sample containing muons and jets has been selected which is enriched in semileptonic b quark decays. The visible cross section \sigma(ep -> b \bar{b}X -> \mu X') for Q^2 < 1 GeV^2, 0.1 < y < 0.8 is measured to be 0.176+-0.016(stat.)+0.026-0.017(syst.) nb for the muons to be detected in the range 35 deg < \theta^\mu < 130 deg and \pt^\mu > 2.0 GeV in the laboratory frame. The expected visible cross section based on a NLO QCD calculation is 0.104+-0.017 nb. The cross sections for electroproduction with Q^2<1 GeV^2 and photoproduction are derived from the data and found to be \sigma(ep-> e b\bar{b}X) = 7.1+-0.6(stat.)+1.5-1.3(syst.) nb and \sigma(\gamma p-> b\bar{b} X) = 111+-10(stat.)+23-20(syst.) at an average <W_{\gamma p}> \sim 180 GeV, respectively.