Five-dimensional CFTs from the ε -expansion

Abstract

We look for UV fixed points of non-abelian $SU(n_c)$ gauge theories in $4+2\epsilon$ dimensions with $n_f$ Dirac fermions in the fundamental representation, using the available five-loop $\overline{{\rm MS}}$ $\beta$-function and employing Pad\'e-Borel resummation techniques and Pad\'e approximants to the series expansion in $\epsilon$. We find evidence for a $5d$ UV-fixed point for $SU(2)$ theories with $n_f\leq 4$ and pure $SU(n_c)$ theories for $n_c\leq 4$. We also compute the anomalous dimensions $\gamma$ and $\gamma_g$ of respectively the fermion mass bilinear and the gauge kinetic term operator at the UV fixed point.