The difference in the angular distributions between beauty quarks and antiquarks, referred to as the charge asymmetry, is measured for the first time in bb¯ pair production at a hadron collider. The data used correspond to an integrated luminosity of 1.0fb−1 collected at 7TeV center-of-mass energy in proton-proton collisions with the LHCb detector. The measurement is performed in three regions of the invariant mass of the bb¯ system. The results obtained are:
where Abb¯C is defined as the asymmetry in the difference in rapidity between jets formed from the beauty quark and antiquark. The beauty jets are required to satisfy 2<η<4, ET>20GeV, and have an opening angle in the transverse plane Δϕ>2.6rad. These measurements are consistent with the predictions of the Standard Model.