Measurement of CP violation in $B_s^0 \to φφ$ decays

Journal article

A measurement of the decay time dependent CP-violating asymmetry in $B_s^0 \to \phi\phi$ decays is presented, along with measurements of the $T$-odd triple-product asymmetries. In this decay channel, the CP-violating weak phase arises from the interference between $B_s^0$-$\bar{B}_s^0$ mixing and the loop-induced decay amplitude. Using a sample of proton-proton collision data corresponding to an integrated luminosity of $3.0\, fb^{-1}$ collected with the LHCb detector, a signal yield of approximately 4000 $B_s^0 \to \phi\phi$ decays is obtained. The CP-violating phase is measured to be ${\phi_s =-0.17\pm0.15\mathrm{\,(stat)}\pm0.03\mathrm{\,(syst)}}$ rad. The triple-product asymmetries are measured to be ${A_U=-0.003\pm0.017\mathrm{\,(stat)}\pm0.006\mathrm{\,(syst)}}$ and ${A_V=-0.017\pm0.017\mathrm{\,(stat)}\pm0.006\mathrm{\,(syst)}}$. Results are consistent with the hypothesis of CP conservation.

Authors: collaboration, L; Aaij, R; Adeva, B; Adinolfi, M; Affolder, A

• Publication status: Published
• Publisher: American Physical Society
• Journal: Phys. Rev. D
• Volume: 90
• Issue: 5
• Pages: 052011
• Publication date: 2014-07-08
• DOI: 10.1103/PhysRevD.90.052011
• EISSN: 1550-2368
• ISSN: 1550-7998
• Language: English
• Keywords: hep-ex