Study of orbitally excited B mesons at CDF

Using data collected by the Run II Collider Detector at Fermilab (CDF), we study the properties of the lowest orbitally excited (L = 1) B mesons, collectively denoted as the $B^{**}$. We reconstruct $B^{**}$ candidates in two $B^+$ decay channels: $B^+ \rightarrow J/\psi K^+$, $J/\psi \rightarrow \mu^+ \mu^-$ and $B^+ \rightarrow \bar{D}^0 \pi^+$, $\bar{D}^0 \rightarrow \K^+ \pi^-$. Through a simultaneous fit of both channels, we measure the masses of the two narrow $B^{**}$ states.