Search for B decays to final states with the η_c meson

We report a search for B decays to selected final states with the η_c meson: B^± → K^±η_cπ⁺π^-, B^± → K^±η_η, B^± → K^±η_cη and B^± → K^±η_cπ⁰. The analysis is based on 772 x 10⁶ BB-bar pairs collected at the Ψ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e⁺e^- collider. We set 90% confidence level upper limits on the branching fractions of the studied B decay modes, independent of intermediate resonances, in the range (0.6-5.3) x 10^-4. We also search for molecular-state candidates in the D⁰D*-bar⁰ - D-bar⁰D*⁰, D⁰D-bar⁰ + D-bar⁰D⁰ and D*⁰D*-bar⁰ + D*-bar⁰D*⁰ combinations, neutral partners of the Z(3900)^± and Z(4020)^±, and a poorly understood state X(3915) as possible intermediate states in the decay chain, and set 90% confidence level upper limits on the product of branching fractions to the mentioned intermediate states and decay branching fractions of these states in the range (0.6-6.9) x 10^-5