Top: Fit to the invariant mass distribution of $\mathrm{D_s^+}$ and $\mathrm{D^+}$ candidates in the $5< \pt <5.5$ GeV/$c$ interval in pp collisions at $\sqrt{s}=13.6$ TeV, reconstructed in the $\mathrm{D_s^+, D^+ \rightarrow \phi\pi^+ \rightarrow K^+K^-\pi^+}$ decay channel. The fit function is composed of a second-degree polynomial function to describe the combinatorial background, a template fit for the $\mathrm{D^+ \rightarrow \pi^+K^-\pi^+}$ correlated background and two gaussian functions to describe the $\mathrm{D_s^+}$ and $\mathrm{D^+}$ peaks. Bottom: Distribution of the difference between the data points and the background function, made of a second-degree polynomial function to describe the combinatorial background, and a template function for the $\mathrm{D^+ \rightarrow \pi^+K^-\pi^+}$ correlated background