Analytical coalescence formula for particle production in relativistic heavy-ion collisions

Based on a covariant coalescence model with a blast-wave-like parametrization for the phase-space configuration of constituent particles at freeze-out, we derive an approximate analytical formula for the yields of clusters produced in relativistic heavy-ion collisions. Compared to previous formulas, the present work additionally considers the contributions from the longitudinal dimension in momentum space, the relativistic corrections, and the finite-size effects of the produced clusters relative to the spatial distribution of constituent particles at freeze-out. The new analytical coalescence formula provides a useful tool to evaluate the yield of produced clusters, such as light nuclei from nucleon coalescence and hadrons from quark coalescence, in heavy-ion collisions. As a first application of the new analytical formula, we explore the strangeness population factor S-3 = (3)(Delta) H/(He-3 x Delta / p) based on nucleon/ Delta coalescence as well as the production of exotic hadrons based on quark coalescence, in central Pb+ Pb collisions at root sNN = 2.76 TeV. The results are compared with the predictions from other models.