Properties of Excited D Mesons
I. Gorelov
UNM

We present the first observation of orbitally excited P--wave D mesons n hadron collisions. These states form a degenerate doublet in the heavy quark symmetry limit with hyperfine mass splitting proportional to $1/m_c$. Using data from the displaced track trigger, CDF II collects the largest world sample of $D1,D2^\ast$ decaying into $D^{(\ast)+}\pi^-$ or $D^+\pi^-. Masses and widths of both states have been measured with precision better than or comparable to the world average.