CDF B spectroscopy results: B^** and B_c

Abstract

We report on two spectroscopy results from CDF. First, we observe the orbitally excited $B^{**}$ mesons in $B \to \ell D^{(*)}X$ events. We find $28 \pm 6 \pm 3$% of light $B$ mesons produced are $B^{**}$ states. A collective mass fit results in a $B_1$ mass of $5.71 \pm 0.02$ GeV/$c^2$. Secondly, we observe $20.4^{+6.2}_{-5.5}$ decays of $B^+_c \to J/\psi \ell^+X$, with a $ 6.40 \pm 0.39 \pm 0.13 {\rm GeV}/c^2$ mass and $ 0.46 ^{+0.18}_{-0.16} \pm 0.03 $ps lifetime. The production rate is in reasonable accordance with expectations.