Measurement of the forward-backward asymmetry in low-mass bottom-quark pairs produced in proton-antiproton collisions

Summary

We report a measurement of the forward-backward asymmetry, ${A}_{\mathrm{FB}}$, in $b\overline{b}$ pairs produced in proton-antiproton collisions and identified by muons from semileptonic $b$-hadron decays. The event sample is collected at a center-of-mass energy of $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ with the CDF II detector and corresponds to $6.9\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity. We obtain an integrated asymmetry of ${A}_{\mathrm{FB}}(b\overline{b})=(1.2\ifmmode\pm\else\textpm\fi{}0.7)%$ at the particle level for $b$-quark pairs with invariant mass, ${m}_{b\overline{b}}$, down to $40\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ and measure the dependence of ${A}_{\mathrm{FB}}(b\overline{b})$ on ${m}_{b\overline{b}}$. The results are compatible wit