$\Lambda_b \rightarrow \Lambda^0 \mu \mu$ angular analysis

The differential branching fraction of the rare decay $\Lambda_{b} \rightarrow \Lambda\mu^{+}\mu^{−}$ is measured as a function of $q^2$, the square of the dimuon invariant mass. The analysis is performed using data collected by the LHCb experiment, corresponding to an integrated luminosity of 3.0 fb$^{−1}$. This includes evidence for signal at $q^2$ below the square of the $J/\psi$ mass with significance above 3$\sigma$. In the $q^2$ intervals where the signal is observed, angular distributions are studied and the forward-backward asymmetries in the dimuon and hadron systems are measured for the first time.