Production of light flavor and single-charmed hadrons in $pp$ collisions at $\sqrt{s}=5.02$ TeV in an equal-velocity quark combination model

Abstract

We apply an equal-velocity quark combination model to study the production of light-flavor hadrons and single-charmed hadrons at midrapidity in $pp$ collisions at $\sqrt{s}=5.02$ TeV. We find experimental data for $p_T$ spectra of $\hat{I}\text{c◯}$ and $\ddot{I}•$ exhibit a quark number scaling property, which is a clear signal of quark combination mechanism at hadronization. Experimental data for $p_T$ spectra of $p$, $\hat{I}›$, $\hat{I}ž$, $\hat{I}\text{c◯}$, $\ddot{I}•$ and $K^{\ast 0}$ are systematically described by the model. The non-monotonic $p_T$ dependence of $\hat{I}\text{c◯}/\ddot{I}•$ ratio is naturally explained and we find it is closely related to the shape of the logarithm of strange quark $p_T$ distribution. Using $p_T$ spectra of light-flavor quarks obtained from light-flavor hadrons and a $p_T$ spectrum of charm quarks which is consistent with perturbative QCD calculations, the experimental data for differential cross-sections of $D^{0,+}$, $D_s^{+}$ and $\hat{I}{›}_c^{+}$ as the function of $p_T$ are systematically described. We predict the differential cross-sections of $\hat{I}{ž}_c^{0,+}$ and $\hat{I}{\text{c◯}}_c^0$. The ratio $\hat{I}{ž}_c^{0,+}/D^0$ in our model is about 0.16 and $\hat{I}{\text{c◯}}_c^0/D^0$ is about 0.012 due to the cascade suppression of strangeness. In addition, the predicted $\hat{I}{ž}_c^{0,+}/D^0$ and $\hat{I}{\text{c◯}}_c^0/D^0$ ratios exhibit the non-monotonic dependence on $p_T$ in the low $p_T$ range.

11 pages, 9 figures