Deuteron production in AuAu collisions at $\sqrt{s_{NN}} = 7-200$ GeV via pion catalysis

Abstract

We study deuteron production using no-coalescence hydrodynamic + transport simulations of central AuAu collisions at $\sqrt{s_{NN}} = 7 - 200$ GeV. Deuterons are sampled thermally at the transition from hydrodynamics to transport, and interact in transport dominantly via $\pi p n \leftrightarrow \pi d$ reactions. The measured proton, Lambda, and deuteron transverse momentum spectra and yields are reproduced well for all collision energies considered. We further provide a possible explanation for the measured minimum in the energy dependence of the coalescence parameter, $B_2(\sqrt{s_{NN}})$ as well as for the difference between $B_2(d)$ for deuterons and that for anti-deuterons, $B_2(\bar{d})$.