An exploration of

Measurements of the mixing phase ϕs appear to be converging towards the SM prediction, suggesting that contributions from New Physics (NP), if present, are small. This poses the question of whether smallish NP in ϕs can be distinguished from the hadronic uncertainties present in the interfering Bs decay mode. In this paper we discuss the potential of extracting ϕs from the decay modes Bs→J/ψη(′) and Bs→J/ψf0(980) and how their respective hadronic uncertainties can be controlled. In addition, we demonstrate how the branching ratios of the former decays can be used to estimate the η−−η′ mixing angles. Finally, we point out that effective lifetime measurements of decay modes such as the Bs→J/ψf0(980) can be used to constrain both ϕs and the Bs decay width difference ΔΓs, complementary to the usual time-dependent tagged analysis.