LHCb: Measurement of the polarization amplitudes of the decay $B^0 \rightarrow J/\psi K^\ast$

Using the data sample recorded with the LHCb detector in 2010 we perform a combined angular and lifetime analysis of the decay $B^0 \rightarrow J/\psi K^\ast$. The data corresponds to an integrated luminosity of about 36 pb$^{-1}$ and was taken at the LHC at an centre-of-mass energy of $\sqrt{s}$= 7 TeV. A total of 3909 $J/\psi K^*$ candidates are found and are used to extract the polarisation amplitudes and the corresponding strong phases for the decays $B_d \rightarrow J/\psi K^\ast$.