  This talk consists of two parts. We first present a light-cone QCD sum rule
computation of the $B_s\to f_0(980)$ form factors which are necessary inputs in
semileptonic and nonleptonic $B_s$ decays into $f_0(980)$. Then we analyze
nonleptonic $B_s$ decays into a charmonium state and a light meson, which are
potentially useful to access the $B_s$-${\bar B}_s$ mixing phase $\beta_s$. We
explore the experimental feasibility of measuring these various channels,
paying attention to different determinations of $\beta_s$ in view of the hints
of new physics recently emerged in the $B_s$ sector.
