Search for B decays to final states with the eta_c meson
We report a search for B decays to selected final states with the eta_c meson: B -> K eta_c pi+ pi-, B -> K eta_c omega, B -> K eta_c eta and B -> K eta_c pi0. The analysis is based on 772 millions of BB pairs collected at the Upsilon (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)10-4. We also search for molecular-state candidates for the D()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 X and decay branching fractions of X in the range (0.6 - 0.9)*10-5.