Gauge contribution to the $1/N_F$ expansion of the Yukawa coupling beta function

Abstract

We provide a closed analytical form for the gauge contribution to the beta function of a generic Yukawa coupling in the limit of large $N_F$, where $N_F$ is the number of heavy vector-like fermions charged under an abelian or non-abelian gauge group. The resummed expression is finite and for the abelian case presents a pole at the same location as for the corresponding gauge beta function. When applied to new physics scenarios characterized by large Yukawa couplings, the contribution calculated here can cure their pathological UV behavior and make the couplings asymptotically free.

Comments: 18 pages, 4 figures. Added clarification on our choice of gauge, which was previously stated incorrectly. Typos fixed. References added