LHCb; Measurement of the forward-central $b \bar{b}$ production asymmetry

CDF and D0 collaborations results suggests that the top-quark forward-backward production asymmetry is much larger than the Standard Model (SM) predictions. Measuring the $b \bar{b}$ asymmetry production would provide constraint on the flavor structure of any model that attempts to explain the CDF and D0 results. A measurement of the forward-central (FC) $b\bar{b}$ production asymmetry is presented based on the LHCb data collected in 2011 at $\sqrt{s}$ = 7 TeV corresponding to an integrated luminosity of 1.0 fb$^{-1}$ using selected events that have two identified $b$ jets, one of which is flavor tagged by one muon with high momentum. The FC asymmetry is defined as \begin{align} A^{b \bar{b}}_{FC}=\frac{N(\Delta y > 0)-N(\Delta y < 0)}{N(\Delta y > 0)+N(\Delta y < 0)} \end{align} where $\Delta y = \mid y_b \mid - \mid y_{\bar{b} \mid}$ is the rapidity difference between $b$ and $\bar{b}$ No SM precise prediction is evaluated but there is a consensus that at Low $M_{b \bar{b}}$ gluon fusion dominates resulting in $\cal{O}$(0.1 %) asymmetry. For $M_{b \bar{b}} > 100$ GeV the expected asymmetry is about $\cal{O}$(0.1 %) where gluon fusion which has no asymmetry is less dominant at high mass.