Resonances and $CP$ violation in $B_s^0$ and $\overline{B}_s^0 \to J/ψK^+K^-$ decays in the mass region above the $ϕ(1020)$

Abstract

The decays of $B_s^0$ and $\overline{B}_s^0$ mesons into the $J/ψK^+K^-$ final state are studied in the $K^+K^-$ mass region above the $ϕ(1020)$ meson in order to determine the resonant substructure and measure the $CP$-violating phase, $ϕ_s$, the decay width, $Γ_s$, and the width difference between light and heavy mass eigenstates, $ΔΓ_s$. A decay-time dependent amplitude analysis is employed. The data sample corresponds to an integrated luminosity of $3{\rm fb}^{-1}$ produced in 7 and 8 Tev $pp$ collisions at the LHC, collected by the LHCb experiment. The measurement determines $ϕ_s = 119\pm107\pm34 {\rm \, mrad}$. A combination with previous LHCb measurements using similar decays into the $J/ψπ^+π^-$ and $J/ψϕ(1020)$ final states gives $ϕ_s=1\pm37 {\rm \,mrad}$, consistent with the Standard Model prediction.

All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2017-008.html