LHCb: Measurement of polarisation amplitudes and triple product asymmetries in the $B_s^0 \to \phi \phi$ decay at LHCb

An untagged, time-integrated analysis of the $B_s^0 \to \phi \phi$ decay has been performed with 1 fb$^{-1}$ of $pp$ collision data at centre-of-mass (COM) energy $\sqrt{s} = 7$ TeV taken using the LHCb detector. Optimised selections have yielded 801 $B_s^0 \to \phi \phi$ events at high signal to background ratio. This has allowed for measurements of polarisation amplitudes ($|A_0|^2$, $|A_{\perp}|^2$, $|A_{\parallel}|^2$) and strong phase difference (cos$\delta_{\parallel}$) to be performed. Measurements of $T$-violating triple product asymmetries have yielded results $A_U = ^- 0.055 \pm 0.036 (stat.) \pm 0.018 (syst.)$ & $A_V = 0.010 \pm 0.036 (stat.) \pm 0.018 (syst.)$.