Measurement of ${C\!P}$ violation parameters and polarisation fractions in ${B_s^0\to J/\psi \overline{K}^{*0}}$ decays

TL;DR

This paper reports the first measurement of ${C m{P}}$ asymmetries, branching fraction, and polarisation in ${B_s^0 o J/\psi ar{K}^{*0}}$ decays, providing insights into ${C m{P}}$ violation and penguin contributions.

Contribution

It provides the first ${C m{P}}$ asymmetry measurements and updated decay parameters for ${B_s^0 o J/\psi ar{K}^{*0}}$, constraining penguin effects in ${C m{P}}$ violation.

Findings

First ${C m{P}}$ asymmetry measurement in this decay mode

Updated branching fraction and polarisation fractions

Constraints on penguin contributions to ${ m{f extphi}_s}$

Abstract

The first measurement of ${C\!P}$ asymmetries in the decay ${B_s^0\to J/\psi \overline{K}^{*}(892)^{0}}$ and an updated measurement of its branching fraction and polarisation fractions are presented. The results are obtained using data corresponding to an integrated luminosity of $3.0\,fb^{-1}$ of proton-proton collisions recorded with the LHCb detector at centre-of-mass energies of $7$ and $8\,\mathrm{TeV}$. Together with constraints from ${B^0\to J/\psi \rho^0}$, the results are used to constrain additional contributions due to penguin diagrams in the ${C\!P}$-violating phase ${{\phi}_{s}}$, measured through ${B_s^0}$ decays to charmonium.