Measurement of $\sigma(b \bar{b})$ with inclusive final states

A measurement of the cross section for the production of $b\bar{b}$ pairs based on $b$ inclusive final states is presented using LHCb data collected from $pp$ collisions at $\sqrt s$= 7 TeV in 2010, corresponding to an integrated luminosity of $\sim$18 pb$^{-1}$. The inclusive $b\bar{b}$ sample is selected on the basis of decay vertices displaced from the primary interaction. The measurement has been performed in a region of pseudorapidity 2.5 $<\eta<$ 4.0 and transverse momentum $p_{\rm{T}}$ $> 5$ GeV of the $b$ hadron candidate. The selected sample is a mixture of $b\bar{b}$ and $c\bar{c}$ events with a negligible contamination of light quarks, a measurement of the cross section for the production of $c\bar{c}$ can therefore be performed simultaneously. The results are $\sigma^{b\bar{b}} = 7.7\pm0.12~\rm{(stat)}\pm0.84~\rm{(syst)}~\mu$b and $\sigma^{c\bar{c}} = 104.6\pm2.7~\rm{(stat)}\pm11.4~\rm{(syst)}~\mu$b, inside the kinematic range defined above.