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 M _ { \odot } -0.7 M _ { \odot } that is strongly peaked between 0.47 M _ { \odot } -0.54 M _ { \odot } .
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 .