Invariant mass of $J/\psi K^+K^-$ combinations. The vertical lines indicate the signal and sideband regions.

Invariant mass of $K^+K^-$ combinations. The histogram shows the data in the signal region while the points (red) show the sidebands.

(a) The $m(K^+K^-)$ distribution for simulated $\overline{B}^0\rightarrow J/\psi \overline{K}_2^*(1430)$ decays where the $\pi^+$ from the $\overline{K}_2^*(1430)$ decay is interpreted as a $K^+$. The histogram shows $m(K^+K^-)$ in the signal region of $\overline{B}_s^0$ mass and the points in the sideband region. The simulation corresponds to approximately 8 fb$^{-1}$ of data. (b) The $m(J/\psi K^+\pi^-)$ distribution for $J/\psi K^+K^-$ data candidates $25-200$ MeV above the $\overline{B}_s^0$ mass, and with $m(K^+K^-)$ within $\pm$300 MeV of 1525 MeV, reinterpreted as $\overline{B}^0\rightarrow J/\psi K^-\pi^+$ events. The fit is to a signal Gaussian whose mass and width are allowed to vary as well as a quadratic background.

Projections of fits to (a) the $\overline{B}_s^0$ candidate mass and (b) the di-kaon mass. The $f'_2$ signal is parameterized by a spin-2 Breit-Wigner function whose width is fixed to 73 MeV (dotted curve). The combinatorial background is shown in the light shaded region, while the darker shaded region shows the non-resonant $J/\psi K^+K^-$ component. The long-dashed (red) line shows the misidentified $\overline{B}^0\rightarrow J/\psi K^-\pi^+$ decays, and the (blue) line the total.

Distribution of $\cos\theta_{J/\psi}$ for $\overline{B}_s^0\rightarrow J/\psi f'_2$ decays. The background and non-resonant $K^+K^-$ components have been subtracted, and the data have been corrected for acceptance. The fit to Eq. 1 is shown by the solid line. Note that for pure S-wave the distribution would be $\sin^2\theta_{J/\psi}$ ($p=0$), shown as the dotted curve, while for pure helicity 1 ($p=1$) the data would be described by the dot-dashed curve.

Animated gif made out of all figures.

Systematic uncertainties on $R$.