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Precision measurements of charm hadron properties at Babar

We present preliminary results on the natural line width, $Γ(D^{*+})$, in the transition $D^{*}(2010)^{+} \rightarrow D^0 π^+$. The $D^0$ is reconstructed in two decay channels: $D^0 \rightarrow K^-π^+$ and $D^0 \rightarrow K^-π^+π^-π^+$. We use Monte Carlo to simulate our reconstruction resolution in the difference of the reconstructed $D^{*+}$ and reconstructed $D^0$ masses. We fit a relativistic P-wave Breit-Wigner form convolved with the measured resolution, together with a background function, to the mass difference distribution. For the decay mode $D^0\rightarrow K^-π^+$ we obtain $Γ= 83.5 \pm 1.7 \pm 1.2$ keV and $Δm = m_{D^{* +}} - m_{D^0} = 145425.5 \pm 0.6 \pm 2.6$ keV, where the quoted errors are statistical and systematic, respectively. For the $D^0\rightarrow K^-π^+π^-π^+$ mode, we do not quote a width measurement at this time, but measure $Δm = m_{D^{* +}} - m_{D^0} = 145426.5 \pm 0.4 \pm 2.6 $ keV. Additionally, we present preliminary results from the decay mode $Λ_c (2880)^+ \rightarrow Λ_c^+π^+π^-$ for the mass, width and quasi-two-body branching ratios of the $Λ_c(2880)^+$ baryon. We measure $m(Λ_c(2880)^+) - m(Λ_c(2286)^+) = 594.9 \pm 0.4 \pm 0.3$ MeV and $Γ(Λ_c(2880)^+) = 6.2 \pm 1.4 \pm 1.5$ MeV, where the errors are statistical and systematic, respectively.