Production of light nuclei in heavy-ion collisions within a multiple-freezeout scenario

We discuss the production of light nuclei in heavy ion collisions within a multiple freezeout scenario. Thermal parameters extracted from the fits to the observed hadron yields are used to predict the multiplicities of light nuclei. Ratios of strange to nonstrange nuclei are found to be most sensitive to the details of the chemical freezeout. The well-known disagreement between data of ${}_{\Lambda }^3\text{H}{/}^3\text{He}$ and $\overline{{}_{\Lambda }^3\text{H}{/}^3\text{He}}$ at $\sqrt{s_{NN}}=200$ GeV and models based on thermal as well as simple coalescence using a single chemical freezeout surface goes away when we let the strange and nonstrange hadrons freeze out at separate surfaces. At the CERN Large Hadron Collider energy of $\sqrt{s_{NN}}=2700$ GeV, multiple freezeout scenario within a thermal model provides a consistent framework to describe the yields of all measured hadrons and nuclei.

Figure 1

Plots of ratios of strange to nonstrange particles versus $\sqrt{s_{NN}}$. The blue bands correspond to 2CFO and red bands to 1CFO. The width of the bands reflect the uncertainties associated with the ratios extracted in the thermal model. The solid inverted triangle and open stars represent the experimentally measured ratios [11, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51].

Figure 2

Plots of ratios of nonstrange particles versus $\sqrt{s_{NN}}$. The blue bands correspond to 2CFO and red bands to 1CFO. The width of the bands reflect the uncertainties associated with the ratios extracted in thermal model. The solid inverted triangles represent the experimentally measured ratios [11, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52].

Figure 3

Few antiparticle to particle ratios of light nuclei. As argued in the text, these ratios are not sensitive to the different freezeout mechanisms.

Figure 4

Thermal model production of hadrons and nuclei at $\sqrt{s_{NN}}=200$ GeV. Here $\sigma$ is the error in the data. The solid inverted triangle represent the experimentally measured ratios [11, 34, 38, 39, 40]. Only the data of hadrons were used to extract the thermal parameters.

Figure 5

Thermal model production of hadrons and nuclei at $\sqrt{s_{NN}}=2700$ GeV. Here $\sigma$ is the error in the data. The solid inverted triangle represent the experimentally measured ratios [53, 54, 55, 56]. Only the data of hadrons were used to extract the thermal parameters.