Which elements are specifically mentioned as being contributed by the s-process in AGB stars?

Barium and Lead

Nucleosynthesis is not solely dependent on the violent core-collapse of supernovae; some elements are created through slower mechanisms in different stellar environments. The slower neutron capture process, known as the s-process, occurs within asymptotic giant branch (AGB) stars, which are generally less massive than the giants destined for core-collapse supernovae. This process allows nuclei time to decay between neutron captures, resulting in the formation of specific stable, heavy elements. The text explicitly notes that elements such as barium and lead are contributed to the universe via this s-process operating within AGB stars, distinguishing them from the elements forged through the rapid neutron capture (r-process) of a supernova.