Measurement of the Weak Mixing Angle and the Spin of the Gluon from Angular Distributions in the Reaction $pp\rightarrow Z/\gamma^* + X \rightarrow \mu^+ \mu^- + X$ with ATLAS

The measurement of the effective weak mixing angle with the ATLAS experiment at the LHC is presented. It is extracted from the forward--backward asymmetry in the polar angle distribution of the muons originating from $Z$ boson decays in the reaction $pp\rightarrow Z/\gamma^*+X\rightarrow\mu^+\mu^-+X$. In total $4.7\,{\rm fb}^{-1}$ of proton--proton collisions at $\sqrt{s}=7\,\TeV$ are analysed. In addition, the full polar and azimuthal angular distributions are measured as a function of the transverse momentum of the $Z/\gamma^*$ system and are compared to several simulations as well as recent results obtained in $p\bar{p}$ collisions. Finally, the angular distributions are used to confirm the spin of the gluon using the Lam-Tung relation.