  We quantify an evolutionary channel for single sdB stars based on mergers of
binaries containing a red giant star and a lower mass main sequence or brown
dwarf companion in our Galaxy. Population synthesis calculations that follow
mergers during the common envelope phase of evolution of such systems reveal a
population of rapidly rotating horizontal branch stars with a distribution of
core masses between 0.32 Mo - 0.7 Mo that is strongly peaked between 0.47 Mo -
0.54 Mo. The high rotation rates in these stars are a natural consequence of
the orbital angular momentum deposition during the merger and the subsequent
stellar contraction of the merged object from the tip of the red giant branch.
We suggest that centrifugally enhanced mass loss facilitated by the rapid
rotation of these stars may lead to the formation of single sdB stars for some
of these objects.
