Searches for Prompt Heavy Quarkonia

We have searched for prompt heavy quarkonia and Bc mesons in 3 × 106 hadronic Z0 decays recorded with the DELPHI detector at LEP. No signal was observed in any of these modes. We achieved the highest sensitivities for gluon fragmentation into J/ψ and for semileptonic B c decays, yielding branching ratio upper limits of B(Z 0 → J/ψggX) < 4.1×10−4 and B(Z0 → B c X)·B(B ± c → J/ψl νl) < 5.0×10 −5 @ 90% CL, respectively. We found the first evidence for radially excited B mesons, by observing a signal in the B(∗)π+π− final state at Q = m(B(∗)π+π−)−m(B(∗))− 2m(π) = 301 ± 4± 10 MeV.