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

Abstract

A measurement of the decay time dependent CP-violating asymmetry in $B_s^0\to \varphi \varphi$ 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 $3.0f{b}^{-1}$ collected with the LHCb detector, a signal yield of approximately 4000 $B_s^0\to \varphi \varphi$ decays is obtained. The CP-violating phase is measured to be ${\varphi }_s=-0.17\pm 0.15(\mathrm{stat})\pm 0.03(\mathrm{syst})$ rad. The triple-product asymmetries are measured to be $A_U=-0.003\pm 0.017(\mathrm{stat})\pm 0.006(\mathrm{syst})$ and $A_V=-0.017\pm 0.017(\mathrm{stat})\pm 0.006(\mathrm{syst})$. Results are consistent with the hypothesis of CP conservation.

19 pages, 7 figures, updated to published version

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• PYTHIA 6.4 Physics and Manual
• Charmless non-leptonic B_s decays to PP, PV and VV final states in the pQCD approach
• Branching fractions, polarisation and asymmetries of B -> VV decays
• Measurement of the CP-violating phase ${\varphi }_s$ in ${\overline{B}}_s^0\to J/\psi {\pi }^{+}{\pi }^{-}$ decays
• Measurement of the polarization amplitudes and triple product asymmetries in the B_s^0 -> phi phi decay

Cited by in corpus (6)

• CP violation in the B system
• Observation of the decay $B_s^0\to \varphi {\pi }^{+}{\pi }^{-}$ and evidence for $B^0\to \varphi {\pi }^{+}{\pi }^{-}$
• Heavy Flavour Physics and CP Violation at LHCb: a Ten-Year Review
• Heavy Flavour Physics at the LHC
• Precision measurement of $CP$ violation in the penguin-mediated decay $B_s^0\to \varphi \varphi$
• Polarisation fractions in $B\to V_1{V}_2$: U-Spin constraints and new physics signatures