Renormalization group analysis of the singularity structure of effective potentials

TL;DR

This paper uses renormalization group techniques to analyze the singularity structure of effective potentials in various quantum field theories, revealing that the singularity shift depends only on one- and two-loop beta functions.

Contribution

It extends previous work by showing that the singularity shift in the effective potential for theories with multiple couplings is determined solely by low-order beta functions.

Findings

The singularity structure is altered when summing contributions to all orders.

The shift in singularity depends only on one- and two-loop beta functions.

This result applies broadly to conformally invariant models like the standard model.

Abstract

Using the renormalization group techniques it was previously shown that the perturbative effective potential in the $\mathcal{O}(N)$ symmetric $\phi^4$ theory, massless scalar electrodynamics as well as in the conformal limit of the standard model can be uniquely determined in terms of the known MS scheme renormalization group functions. Furthermore, re-summation of the leading order corrections plus portions of these higher order contributions to the effective potential in the $\mathcal{O}(N)$ symmetric $\phi^4$ theory shows a peculiar shift in the usual "Landau singularity" apparent in the individual leading order corrections. In this work, we have further investigated this shift by extending the result for theories having multiple couplings. We have shown that the singularity structure of the effective potential as seen by summing up portions of the $V_{N^{P+n}LL}$ for any finite $P$ is altered as expected when these perturbative contributions are summed to all orders but more significantly we found that this shift in the singularity is completely determined by the one and two loop beta functions only. We argue that this is a general result which applies to the conformally invariant standard model.