Subcritical hybrid inflation in a generalized superconformal model

We study a generalized superconformal model that gives rise to subcritical regime of $D$-term hybrid inflation. Exhibiting the both in Jordan frame and Einstein frame, effective potential is derived frame. It turns out inflaton-waterfall field dynamics leads various types inflaton potential. Consequently tensor-to-scalar ratio found range from $10^{-4}$ ($10^{-3}$) $0.1$ for getting 60 (50) $e$-folds before end