Inclusive $b$-jet production cross section measurement at LHCb

The LHCb detector features an outstanding capability to identify displaced secondary vertices with respect to the interaction point. The extraordinary performance of the whole LHCb tracking system makes possible accurate measurements for particles’ trajectories and momenta. Many lifetime and kinematic based properties of the decay of the long-lived $B$ hadrons are at the basis of the identification of $b$-jets, thus the LHCb detector could prove to be suitable to perform QCD studies based on heavy-quark jets. The aim of the analysis is to calculate the inclusive $b\bar{b}$ quark pair production cross section inside the range $\eta \in$ (2.5, 4.0). For this purpose, a $cone$ jet algorithm has been developed to reconstruct and identify jets from the $B$ decay. It relies on how well the measured $B$ hadron approximates the properties of the $b$ quark in order to infer the cross section of $b$ quarks production. The measurement has been performed using 17.7 pb$^{-1}$ of data, about ½ of the total luminosity collected in 2010 at 7Tev. Background from $c$-jets and light quarks and gluons have been studied using LHCb Monte Carlo simulations. The $b\bar{b}$ production cross has been found to be $\sigma^{b\bar{b}}$ = 80.6 $\pm$ 1.2 (stat) $\pm$ 11.4 (syst) $\mu$b, compatible within 1 sigma with NLO predictions.