Decays of metastable vacua in SQCD

TL;DR

This paper numerically estimates decay rates of metastable vacua in SQCD models, confirming analytical scaling laws and showing that certain decays are sufficiently suppressed for phenomenological viability.

Contribution

It provides numerical analysis of decay rates in ISS-type models, validating previous analytical estimates and exploring effects of R-symmetry breaking and spectator fields on vacuum longevity.

Findings

Decay rates towards SUSY vacua match analytical scaling laws.

R-symmetry breaking interactions suppress decay rates sufficiently.

ISS vacua can be long-lived even with spectator fields and R-symmetry breaking.

Abstract

The decay rates of metastable SQCD vacua in ISS-type models, both towards supersymmetric vacua as well as towards other nonsupersymmetric configurations arising in theories with elementary spectators, are estimated numerically in the semiclassical approximation by computing the corresponding multifield bounce configurations. The scaling of the bounce action with respect to the most relevant dimensionless couplings and ratios of scales is analyzed. In the case of the decays towards the susy vacua generated by nonperturbative effects, the results confirm previous analytical estimations of this scaling, obtained by assuming a triangular potential barrier. The decay rates towards susy vacua generated by R-symmetry breaking interactions turn out to be more than sufficiently suppressed for the phenomenologically relevant parameter range, and their behavior in this regime differs from analytic estimations valid for parametrically small scale ratios. It is also shown that in models with spectator fields, even though the decays towards vacua involving nonzero spectator VEVs don't have a strong parametric dependence on the scale ratios, the ISS vacuum can still be made long-lived in the presence of R-symmetry breaking interactions.