Measurement of the production cross section of W bosons in association with two b jets in pp collisions at sqrt(s)=7 TeV

The production of $\mathrm{W}$ bosons in association with b quarks is studied using proton proton collisions at $\sqrt{s} = 7~\mathrm{TeV}$ with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of $5.0~\mathrm{fb}^{-1}$. The $\mathrm{W+b\bar{b}}$ events are selected in the $\mathrm{W}\rightarrow\mu\nu$ decay mode with a muon of $p_{T}>25~\mathrm{GeV}$ and $|\eta|<2.1$, and exactly two b-tagged jets with $p_{T}>25~\mathrm{GeV}$ and $|\eta|<2.4$. The cross section is computed from the reconstructed objects unfolded to the level of final-state particles, corresponding to events with a muon and two particle jets matching the kinematic definitions above, and further requiring the particle jets to be matched to b hadrons. The measured product of the particle-level cross section times the $\mathrm{W}\rightarrow\mu\nu$ branching ratio is $0.53\pm 0.05~\textrm{stat} \pm 0.09 ~\textrm{syst} \pm 0.06 ~\textrm{theo} \pm 0.01~\textrm{lumi} ~\textrm{pb}$, in agreement with the standard model prediction.