Forward-backward asymmetry of Drell-Yan pairs

We present a measurement of the forward-backward asymmetry (A$_{\rm FB}$) for opposite charge lepton pairs produced via an intermediate Z/$\gamma^*$ at $\sqrt{s}$ = 7 TeV in the CMS experiment. Our results are based on an integrated luminosity of 4.7 fb$^{-1}$. We present A$_{\rm FB}$ as a function of the di-lepton mass for ${\rm M}_{\ell^{+}\ell^{-}}>$ 40 GeV, the raw A$_{\rm FB}$ for both di-muons and di-electrons and the combined measurement at the Born level. The di-muon channel and the combined A$_{\rm FB}$ measurements represent the first such measurements at a hadron collider. We find that the A$_{\rm FB}$ distributions are consistent with the Standard Model predictions within uncertainties.