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Measurement of the $CP$-violating phase $\phi_s$ in $B^0_s \to J/\psi\phi$ decays in ATLAS at 13 TeV

The collaboration
CERN-EP-2019-218, 2020.

Abstract (data abstract)
A measurement of the $B^0_s \to J/\psi\phi$ decay parameters using 80.5 $\mathrm{fb}^{-1}$ of integrated luminosity collected with the ATLAS detector from 13 TeV proton–proton collisions at the LHC is presented. The measured parameters include the $CP$-violating phase $\phi_s$, the width difference $\Delta\Gamma_{s}$ between the $B^0_s$ meson mass eigenstates and the average decay width $\Gamma_{s}$. The values measured for the physical parameters are combined with those from 19.2 $\mathrm{fb}^{-1}$ of 7 TeV and 8 TeV data, leading to the following: \begin{eqnarray*} \phi_s & = & -0.087\phantom{0} \pm 0.036\phantom{0} ~\mathrm{(stat.)} \pm 0.021\phantom{0} ~\mathrm{(syst.)~rad} \\ \Delta\Gamma_{s} & = & \phantom{-}0.0657 \pm 0.0043 ~\mathrm{(stat.)} \pm 0.0037 ~\mathrm{(syst.)~ps}^{-1} \\ \Gamma_{s} & = & \phantom{-}0.6703 \pm 0.0014 ~\mathrm{(stat.)} \pm 0.0018 ~\mathrm{(syst.)~ps}^{-1} \\ \end{eqnarray*} Results for $\phi_s$ and $\Delta\Gamma_{s}$ are also presented as 68\% confidence level contours in the $\phi_s$--$\Delta\Gamma_{s}$ plane. Furthermore, the transversity amplitudes and corresponding strong phases are measured. $\phi_s$ and $\Delta\Gamma_{s}$ measurements are in agreement with the Standard Model predictions.

• #### Table 1

Results of Table 6 in the Paper, for Solution (a).

10.17182/hepdata.103066.v1/t1

Fitted values for the physical parameters of interest with their statistical and systematic uncertainties, for the result of solution (a).

• #### Table 2

Results of Table 6 in the Paper, for Solution (b).

10.17182/hepdata.103066.v1/t2

Fitted values for the physical parameters of interest with their statistical and systematic uncertainties, for the result of solution (b).

• #### Table 3

Results of Table 7 in the Paper, for Solution (a).

10.17182/hepdata.103066.v1/t3

Fit correlations between the physical parameters of interest, obtained from the fit for solution (a).

• #### Table 4

Results of Table 8 in the Paper, for Solution (b).

10.17182/hepdata.103066.v1/t4

Fit correlations between the physical parameters of interest, obtained from the fit for solution (b).

• #### Table 5

Results of Table 9 in the Paper, for Solution (a).

10.17182/hepdata.103066.v1/t5

Values of the physical parameters extracted in the combination of solution (a) of 13 TeV results with those obtained from...

• #### Table 6

Results of Table 9 in the Paper, for Solution (b).

10.17182/hepdata.103066.v1/t6

Values of the physical parameters extracted in the combination of solution (b) of 13 TeV results with those obtained from...

• #### Table 7

Results of Table 10 in the Paper, for Solution (a).

10.17182/hepdata.103066.v1/t7

Correlation matrix of the BLUE combination of the 7 TeV and 8 TeV results and the solution (a) of the...

• #### Table 8

Results of Table 11 in the Paper, for Solution (b).

10.17182/hepdata.103066.v1/t8

Correlation matrix of the BLUE combination of the 7 TeV and 8 TeV results and the solution (b) of the...

• #### Table 9

Results of Table 5 in the Paper.

10.17182/hepdata.103066.v1/t9

Summary of systematic uncertainties assigned to the physical parameters of interest.