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

An untagged, time-integrated analysis of the $B_s \to \phi \phi$ decay has been performed with 1 fb$^{-1}$ of pp collision data at centre-of-mass energy $\sqrt{s} = 7$ TeV taken using the LHCb detector. Optimised selections have yielded 801 $B_s \to \phi \phi$ 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. T-violating triple product asymmetries have yielded results $A_U=-0.055 \pm 0.036\mathrm{(stat.)} \pm 0.018\mathrm{(syst.)}$ and $A_V = 0.010 \pm 0.036\mathrm{(stat.)} \pm 0.018\mathrm{(syst.)}$.