Measurements of the polarisation amplitudes and triple product asymmetries in $B_s^0 \to \phi\phi$

Using fb$^{−1}$ of $pp$ collision data collected at center of mass energy $\sqrt{s}$= 7 TeV during 2011 by the LHCb detector. Measurements of the triple product asymmetries, polarisation amplitudes and strong phase difference in the decay $B^0 \to \phi\phi$ are presented.