Invariant-mass (mass-difference) distribution of $\Dzero$, $\Dplus$, and $\Dstar$ meson candidates in different $\pt$ intervals for the centrality class 0--10$\%$. The fit functions are composed of a Gaussian function for the signal and an additional term for the background, as described in detail in the text. The values for the Gaussian mean $\mu$, width $\sigma$, and raw yield S are also reported. Top row: $\Dzero$-meson candidates with $0<\pt<1~\gevc$ without reconstructing the decay vertex. The invariant-mass distributions are shown before (left) and after (right) the subtraction of the combinatorial background estimated from event-mixing Middle row: $\Dzero$-meson candidates with $1<\pt<1.5~\gevc$ with reconstruction of the decay vertex before (left) and after (right) background subtraction. The width of the Gaussian in this and in the previous $\pt$ interval is fixed to the value obtained from simulations. Bottom row: $\Dplus$-meson candidates with $5<\pt<5.5~\gevc$ (left) and $\Dstar$-meson candidates with $16<\pt<24~\gevc$ (right).