A measurement of ∆Γ_{s ​}

Using a dataset corresponding to 9 fb⁻¹ of integrated luminosity collected with the LHCb detector between 2011 and 2018 in proton-proton collisions, the decay-time distributions of the decay modes B⁰_s→J/ψη′ and B⁰_s→J/ψπ⁺π⁻ are studied. The decay-width difference between the light and heavy mass eigenstates of the B0s meson is measured to be ΔΓ_s=0.087±0.012±0.009ps⁻¹, where the first uncertainty is statistical and the second systematic.