If quark-gluon plasma (QGP)–like medium is created in $p$-Pb collisions at extremely high collision energies, charm quarks that move in the medium can hadronize by capturing the comoving light quark(s) or antiquark(s) to form the charm hadrons. Using light quark $p_T$ spectra extracted from the experimental data of light-flavor hadrons and a charm quark $p_T$ spectrum that is consistent with perturbative QCD calculations, the central-rapidity data of $p_T$ spectra and the spectrum ratios for $D$ mesons in the low-$p_T$ range ($p_T\lesssim 7$ GeV/$c$) in minimum-bias $p$-Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV are well described by the quark combination mechanism in equal-velocity combination approximation. The ${\mathrm{\Lambda }}_c^{+}/D^0$ ratio in quark combination mechanism exhibits the typical increase-peak-decrease behavior as the function of $p_T$, and the shape of the ratio for $p_T\gtrsim 3$ GeV/$c$ is in agreement with the data of the ALICE Collaboration in central rapidity region $-0.96<y<0.04$ and the preliminary data of the LHCb Collaboration in forward rapidity region $1.5<y<4.0$. The global production of single-charm baryons is quantified using the data and the possible enhancement (relative to light flavor baryons) is discussed. The $p_T$ spectra of ${\mathrm{\Xi }}_c^0, {\mathrm{\Omega }}_c^0$ in minimum-bias events and those of single-charm hadrons in high-multiplicity event classes are predicted, which serves as the further test of the possible change of the hadronization characteristic for low-$p_T$ charm quarks in the small system created in $p$-Pb collisions at Large Hadron Collider energies.

We show that the experimental data of midrapidity $p_T$ spectra for $p$, $\mathrm{\Lambda }$, $\mathrm{\Xi }$, ${\mathrm{\Omega }}^{-}$, ${\mathrm{K}(892)}^{*0}$, and $\mathrm{\Xi }(1530{)}^{*0}$ in minimum-bias $pp$ collisions at $\sqrt{s}=7\mathrm{TeV}$ can be well fitted by the quark combination mechanism with the parametrized up(down) quark spectrum and strange quark spectrum at hadronization. The averaged transverse momentum $⟨p_T⟩$ and spectrum ratios such as $\mathrm{\Xi }/\mathrm{\Lambda }$ and $\mathrm{\Omega }/\varphi$ calculated from quark combination reproduce the data quite well. The available data of hadronic $p_T$ spectra released by ALICE collaboration in the first three high-multiplicity classes of $pp$ collisions at $\sqrt{s}=7\mathrm{TeV}$ are also well fitted. The extracted quark spectra at hadronization exhibit a dependence on the multiplicity class and also show a certain similarity to those obtained in $p\text{−}\mathrm{Pb}$ collisions at LHC and in relativistic heavy ion collisions. We make predictions for other hadrons, and propose two scaling behaviors among decuplet baryons and vector mesons as the effective probe of hadron production mechanism at such high collision energies.

Experimental data at Relativistic Heavy Ion Collider and Super Proton Synchrotron energies suggest a systematic correlation between yield ratio $\overline{p}/p$ and $K^{-}/K^{+}$, which reveal some universality of hadron production in relativistic heavy ion collisions. We propose an explanation based on the quark combination mechanism that focuses on the production asymmetry between baryons and antibaryons. We start from the basic ideas of quark combination to carry out a general analysis of the properties of the global production of baryons and mesons and obtain the yields of baryons, antibaryons, and mesons as functions of the number of constituent quarks and antiquarks just before hadronization. In particular, we study effects of quark-antiquark asymmetry on the ratio of (anti-)baryons to mesons and that of antibaryons to baryons. We use these formula to well explain the data of $\overline{p}/p$ and $K^{-}/K^{+}$ at different of collision energies and rapidities and suggest further measurements at moderate RHIC energies in the mid-forward rapidity regions to make the decisive test of this universality.

We show that the experimental data of transverse momentum ($p_T$) spectra of $\mathrm{\Omega }$ baryon and $\varphi$ meson at midrapidity in heavy-ion collisions exhibit the constituent quark number scaling in a wide energy range from the Relativistic Heavy Ion Collider to the Large Hadron Collider. Such a scaling behavior is a direct consequence of quark combination mechanism via equal velocity combination and provides a very convenient way to extract the $p_T$ spectrum of strange quarks at hadronization. We present the results of strange quarks obtained from the available data and study the properties in particular the energy dependence of the averaged transverse momentum $\langle p_T\rangle$ and the transverse radial flow velocity $\langle \beta \rangle$ with a hydrodynamics-motivated blast-wave model.

Yield ratios of identified hadrons observed in high multiplicity $p+p$ and $p+\text{Pb}$ collisions at the CERN Large Hadron Collider show remarkable similarity with those in $\text{Pb}+\text{Pb}$ collisions, indicating some important and universal underlying dynamics in hadron production for different quark gluon final states. We use the quark combination model to explain the data of yield ratios in these three collision systems. The observed $p/\pi$ and $\mathrm{\Lambda }/K_s^0$ can be reproduced simultaneously by quark combination, and these two ratios reflect the probability of baryon production at hadronization which is the same in the light sector and strange sector and is roughly constant in $p+p, p+\text{Pb}$, and $\text{Pb}+\text{Pb}$ collision systems over three orders of magnitude in charged particle multiplicity. The data of $K_s^0/\pi , \mathrm{\Lambda }/\pi , \mathrm{\Xi }/\pi$, and $\mathrm{\Omega }/\pi$ show a hierarchy behavior relating to the strangeness content and are naturally explained by quark combination both in the saturate stage at high multiplicity and in the increase stage at moderate multiplicity. Our results suggest that the characteristic of quark combination is necessary in describing the production of hadrons in small systems created in $p+p$ and $p+\text{Pb}$ collisions.