Different coalescence sources of light nucleus production in Au-Au collisions at GeV* *Supported in part by the National Natural Science Foundation of China (12175115,12375074), the Natural Science Foundation of Shandong Province, China (ZR2020MA097), and the Higher Educational Youth Innovation Science and Technology Program of Shandong Province, China (2020KJJ004, 2019KJJ010)

Abstract

We study the production of light nuclei in the coalescence mechanism of Au-Au collisions at midrapidity at GeV. We derive analytic formulas of the momentum distributions of two bodies, three bodies, and four nucleons coalescing into light nuclei and naturally explain the transverse momentum spectra of the deuteron (d), triton (t), helium-3 (3He), and helium-4 (4He). We reproduce data on the yield rapidity densities, yield ratios, and averaged transverse momenta of d, t, 3He, and 4He and provide the proportions of contributions from different coalescence sources for t, 3He, and 4He in their production. We find that besides nucleon coalescence, nucleon+nucleus coalescence and nucleus+nucleus coalescence may play requisite roles in light nucleus production in Au-Au collisions at GeV.