Probing $b\bar{b}$ production with the ATLAS detector at the LHC

This thesis describes the measurement of $b\bar{b}$ production with two different techniques, both using the ATLAS detector at the LHC. Firstly Z + $b\bar{b}$ events are measured using √s = 7 TeV data collected in 2011. The Z-boson was reconstructed using pairs of leptons $(Z → e^+e^−or Z → µ^+µ^−)$, with the b-jets used to tag the presence of B-hadrons. The cross-section was measured as a function of four variables and compared to theoretical predictions. NLO predictions from MCFM and aMC@NLO best reproduce the data with a discrepancy seen at low angular separation of the b-jets. Secondly inclusive $b\bar{b}$ production is probed using the decay of Bhadrons to muons using the √s = 8 TeV data collected by ATLAS in 2012. Differential cross-sections were measured as a function of six variables and compared to predictions from pythia8 and herwig++. In general the shape of data was well reproduced by the herwig++ prediction.