Supersymmetric mass spectra and the seesaw scale

TL;DR

This paper investigates how supersymmetric mass spectra can reveal the seesaw scale using full 2-loop RGEs and minimal Supergravity, showing potential for distinguishing seesaw types with future collider data.

Contribution

It provides a detailed analysis of supersymmetric spectra within type-II and type-III seesaw models, including error estimates for collider measurements and their impact on identifying the seesaw scale.

Findings

ILC measurements can distinguish seesaw types in most cases.

LHC data alone may indicate seesaw presence in favorable parameter regions.

Accurate error estimation is crucial for detecting seesaw signatures in SUSY spectra.

Abstract

Supersymmetric mass spectra within two variants of the seesaw mechanism, commonly known as type-II and type-III seesaw, are calculated using full 2-loop RGEs and minimal Supergravity boundary conditions. The type-II seesaw is realized using one pair of 15 and $\bar{15}$ superfields, while the type-III is realized using three copies of $24_M$ superfields. Using published, estimated errors on SUSY mass observables attainable at the LHC and in a combined LHC+ILC analysis, we calculate expected errors for the parameters of the models, most notably the seesaw scale. If SUSY particles are within the reach of the ILC, pure mSugra can be distinguished from mSugra plus type-II or type-III seesaw for nearly all relevant values of the seesaw scale. Even in the case when only the much less accurate LHC measurements are used, we find that indications for the seesaw can be found in favourable parts of the parameter space. Since our conclusions crucially depend on the reliability of the theoretically forecasted error bars, we discuss in some detail the accuracies which need to be achieved for the most important LHC and ILC observables before an analysis, such as the one presented here, can find any hints for type-II or type-III seesaw in SUSY spectra.