Impact of generalized Yukawa interactions on the lower Higgs mass bound

TL;DR

This paper studies how higher-dimensional operators in Higgs-Yukawa interactions affect the lower Higgs mass bound, showing they can relax the bound and shift the new physics scale without causing metastability, using functional renormalization group methods.

Contribution

It demonstrates that generalized Yukawa interactions and higher-order operators slightly relax the lower Higgs mass bound and clarifies the convergence of renormalization group projection schemes.

Findings

Higher-order Yukawa operators reduce the lower Higgs mass bound.

The shift in the new physics scale can be several orders of magnitude.

Convergence properties of RG schemes are clarified.

Abstract

We investigate the impact of operators of higher canonical dimension on the lower Higgs mass consistency bound by means of generalized Higgs-Yukawa interactions. Analogously to higher-order operators in the bare Higgs potential in an effective field theory approach, the inclusion of higher-order Yukawa interactions, e.g., $\phi^3\bar{\psi}\psi$, leads to a diminishing of the lower Higgs mass bound and thus to a shift of the scale of new physics towards larger scales by a few orders of magnitude without introducing a metastability in the effective Higgs potential. We observe that similar renormalization group mechanisms near the weak-coupling fixed point are at work in both generalizations of the microscopic action. Thus, a combination of higher-dimensional operators with generalized Higgs as well as Yukawa interactions does not lead to an additive shift of the lower mass bound, but relaxes the consistency bounds found recently only slightly. On the method side, we clarify the convergence properties of different projection and expansion schemes for the Yukawa potential used in the functional renormalization group literature so far.