Heterotic enhançon

The enhançon mechanism is studied in heterotic string theory. We consider the $N_L=0\mathrm{}$ winding strings with momentum $(\mathrm{NS}1-{\mathrm{W}}^{*})$ and the Kaluza-Klein dyons $(\mathrm{KK}5\mathrm{}-{\mathrm{NS}5\mathrm{}}^{*}).\mathrm{}$ The $\mathrm{NS}1-{\mathrm{W}}^{*}$ and $\mathrm{KK}5-\mathrm{NS}{5}^{*}$ systems are dualized to the $\mathrm{D}4-\mathrm{D}{0}^{*}$ and $\mathrm{D}6-\mathrm{D}{2}^{*}$ systems, respectively, under the $d=6\mathrm{}$ heterotic–type-IIA S duality. The heterotic form has a number of advantages over the type IIA form. We study these backgrounds and obtain the enhançon radii by brane probe analysis. The results are consistent with S duality.