  The abundances of the slow neutron-capture (s-) process elements observed in
barium stars can be explained by considering mass transfer in a binary system
from an asymptotic giant branch (AGB) star onto a smaller mass and less evolved
binary companion star. Based on the abundances of neutron-capture elements the
barium stars are broadly divided into two categories, "strong" and "mild"
barium stars. However, an understanding of the role of the characteristic
properties of the companion AGBs on the formation of the different types of
barium stars is still lacking. This work focuses on investigating the role of
the mass of the companion AGB stars in this context. In a recent
high-resolution spectroscopic study, we studied in detail the chemical
composition of a few barium stars that we have identified. In order to
understand the nature and the mass of the companion stars, we first estimated
the mass of these objects and then used a parametric model-based analysis to
derive the masses of the primary companion stars. The calculation is extended
to 205 barium stars taken from literature. An analysis of the mass distribution
revealed that both the strong and the mild barium stars occupy the same range
of masses. However, their companion AGB stars' mass distributions peak at two
different values 2.5 M$_{\odot}$ and 3.7 M$_{\odot}$, for the strong and the
mild barium stars respectively. This provides clear evidence that the formation
of mild and strong Ba stars is greatly influenced by the initial masses of the
companion AGB stars. It remains, however, to be seen the possible impact of
other factors such as orbital period and metallicity on the formation scenarios
of barium stars.
